SlideShare ist ein Scribd-Unternehmen logo
1 von 35
HEAT TREATMENT DEFECTS ON
BEARING STEELS
INTERNAL GUIDE :- Mrs MINAL DANI
EXTERNAL GUIDE :- Mr SHASHIKANT JHA
Mr VANRAJ RAJ
RUPAPARAARUN(110130121004)
MAKKA PALAK(110130121047)
MIRAJ PATEL(110130121061)
CONTENTS
• INTRODUCTION
• HEAT TREATMENT PROCESSES
• HEAT TREATMENT DEFECTS IN BEARING
• REMEDIAL MEASURES
• CONCLUSION
• REFERENCES
INTODUCTION
BEARINGS????
• Bearing is a machine element, which supports another moving machine element permitting the
relative motion between the Contact surfaces with minimal friction.
• Bearings application :-
• Cars
• Trains
• Airplanes
• Washing machines
• Refrigerators
• Air conditioners
• Vacuum cleaners
• Photocopy machines
• Computers
• Satellites
INTRODUCTION
BEARING PARTS
BALL BEARING CAGE OUTER RING INNER RING ROLLING ELEMENT
INTRODUCTION
BEARING GRADES
Bearing
grade
C% Si% Mn% P% Cr% Mo% Ni%
S%
AISI
52100
USA
0.95-1.1 0.15-0.35 0.5max 0.012max 1.3-1.6 0.08max 0.25max 0.25max
100Cr6
Germany
0.95-1.1 0.15-0.35 0.25-0.45 0.03 max 1.35-1.65 0.1 max - 0.2 max
SUJ2
JAPAN
0.95-1.1 0.15-0.35 0.5 max 0.025 max 1.3-1.6 0.08 max 0.25 max 0.25 max
GCr15
CHINA
0.95-1.05 0.15-0.35 0.25-0.45 0.027 max 1.4-1.65 0.1 max 0.23 max 0.2 max
 At ABC we studied and experimented only on Bearing Grade AISI 52100.
INTRODUCTION
OPERATIONAL STEPS FOR BEARING
INTRODUCTION
MICROSTRUCTURE
Carbides
(Spheroids)
Pearlite
Carbides
(Spheroids)
Tempered
Martensite
Grain
Boundary
Wire coil ( raw material) ---- Made
Roller.
Cold Heating Operation
Soft Tumbling
Heat Treatment
Grinding
Honing
Grading and Visual Inspection
Bearing Assembly
Austenizing
(740oC – 800oC)
Oil Quenching
(90oC)
Liquid Cooling
(0oC - 5oC)
Tempering
(130oC – 160oC)
Air Cooling
Round bar (raw material)--- Made inner &
outer ring.
Hot forging
Spherodized
Annealing
Turning
Heat treatment
Face/ OD Grinding
Bore, Track & Flange grinding
Honing & Etching
Bearing assembly
Austenizing
(740oC – 800oC)
Oil Quenching
(90oC)
Liquid Cooling
(0oC - 5oC)
Tempering
(130oC – 160oC)
Air Cooling
HEAT TREATMENT
FURNACE
HEAT TREATMENT PROCESS
SPHEROIDIZED ANNEALING :-
• Spheroidization is achieved by holding the metal for a prolonged period at austenizing temperature and
cooling at a very slow rate by along with appropriate soaking time.
• Spheroidize annealing is done to form spheroids of carbon to improve machinability and prepare the metal
structure for hardening.
• Temperature: up to 860OC
• Cycle time: about 48 to 54 hours with slow furnace cooling along with intervals of socking time.
QUENCHING :-
• Cooling a metal at a rapid rate.
• Used to produce a martensitic transformation.
• Often produce a harder metal in ferrous, softer than normal in non ferrous.
• Metal heated above the upper critical temperature and then quickly cooled.
• Quenchant : Ferro-quench oil.
• Temperature : 90OC
• Cycle time : 8 mins
HEAT TREATMENT PROCESS (CONT..)
INDUCTION HARDENING :-
• A surface hardening technique.
• Surface of the metal is heated very quickly, using a no-contact method.
• Martensitic transformation at the surface, leaving the underlying metal unchanged after quenching.
• Creates a very hard, wear resistant surface maintaining toughness in the majority of the object.
FLAME HARDENING :-
• Used to harden only a portion of a metal.
• Only a portion of the metal is heated before quenching.
• Often produces an extremely brittle zone between the heated metal and the unheated metal, as cooling at
the edge of this heat affected zone is extremely rapid.
HEAT TREATMENT PROCESS (CONT..)
NITRIDING :-
• Creates a case hardened surface by diffusing nitrogen into the surface of a metal.
• Commonly used on low-carbon, low-alloy steels, medium and high-carbon steels, titanium,
aluminium and molybdenum.
TEMPERING :-
• Usually performed after hardening, reduce some of the excess hardness.
• Heating the metal at temperature below the critical temperature for a certain period of time.
• Air cooling.
• It controls brittleness caused after quenching and retain its strength and toughness.
• Produces martensitic + austenitic structure.
• Temperature : 175OC – 210OC
• Cycle time : 3 hours
MECHANICAL TESTING
Hardness Testing :-
• Before Heat Treatment :
25 – 30 BHN
• After Quenching : 64 – 65
BHN
• After Tempering : 61 – 62
BHN
Oval Distortion Testing :-
• Final Turning Ring(FTR) :
10 – 30µ
• Heat Treated Ring(HTR) :
<150µ
• Total material of ring after
removing ovality : >250µ
HEAT TREATMENT DEFECTS
• Less Supply Of Endo Gas
• Improper Oil Curtain
• Incoming (Raw Material) Problem
• Power Failure
• Oxygen In F/C. (Disturb Inert Atmosphere)
SURFACE DECARBURIZATION :-
• Thermal gradient in the component
• Over heating
• Non-uniform cooling
• Severe quenching
• Improper tempering
• Design defects
QUENCHING CRACKS :-
Grain
Boundary
Full Decarburization
Partial
Decarburization
Carbides
Ok Not ok
Surface Decarburization
Quenching Cracks
HEAT TREATMENT DEFETS (CONT..)
• Furnace Atmosphere
• Poor Quality Quenching Medium
• Dirty Component Surface
• Defective Initial Microstructure
SOFT SPOT :-
• Poor Quality Quenching Medium
• Thermal Gradient before Quenching
• Section Thickness Variation of the Components
• Component’s Shape, Dimensions & Position During Quenching
• Agitation of Quenching Medium
• Initial Microstructure of Material
HEAT TREATMENT DEFORMATION :-
Soft Spots
Heat Treatment Deformation
HEAT TREATMENT DEFECTS (CONT..)
• Non uniform Microstructure
• Unwanted Phase
• Grain Growth
• Grain Boundary Precipitation
• Retained Austenite
• Decarburization
MICRO STRUCTURAL DEFECTS :-
• Lower & Higher Hardening Temperature.
• Heater Failure/Power Failure/Disturb Inert Atmosphere.
• Less Soaking Time During Hardening
LOW HARDNESS :-
• Lower Soaking Time
• Lower Tempering Temperature
HIGH HARDNESS :-
Carbides
(Spheroids)
Carbides
(Spheroids)
Tempered
Martensite
Ok Not Ok
Micro Structural Defects
REMEDIAL MEASURES
Heat Treatment Deformation
 Residual stresses that cause shape change when they exceed material yield strength. This occurs on heating
when the strength properties decline.
 Stresses caused by differential expansion due to thermal gradients. These stresses increase with the thermal
gradient and cause plastic deformation as the yield strength is exceeded.
 Volume changes due to transformational phase change. These volume changes are contained as residual
stress systems until the yield strength is exceeded.
REMEDIAL MEASURES
OVALITY
• Ovality is a certain type of circularity deviation. Ovality results from non-symmetrical distribution of internal
tensions before hardening and uneven heating and cooling.
• Devices using very accurate rotational tables or spindles are used to measure circularity. The axis of the
component is the measuring base in this method. The measuring device ensures very high accuracy, often
better than 1 μm.
• Ovality is checked after Quenching. A special diameter gauge (Figure) that included a dial deviation meter
was used to measure ovality.
• Ovality was measured on 10-20 rings so that an ovality deviation was recorded after each rotation. The
following procedure was applied :
• A bearing ring was inserted into the gauge and was rotated manually.
• A value was read from the deviation meter after each rotation.
• If the deviation was higher than 150 μm, the ring being measured was discarded. It did not meet quality
criteria and could not be passed on for subsequent hard machining.
HEAT TREATMENT DEFORMATION
OVALITY MEASURING GAUGE
REMEDIAL MEASURE (CONT..)
1. Heat Treatment Deformation:
• Preheating of bearing prior to heat treatment.
• Reduce hardening temperature and slow heating.
• Keeping 5 zone in hardening so that it can achieve required temperature at desired cycle time.
• Rate of cooling after hardening should be less.
• Bolting the ring and re-tempering.
REMEDIAL MEASURES (CONT..)
2. Surface Decarburization :
• By controlling furnace atmosphere, i.e., by generating “Endothermic Gas(Endo Gas)”
and producing it inside furnace and controlling its carbon potential.
• Carbon potential : 0.94% – 0.97%
• This will allow carbon inside bearing to stay in equilibrium with the atmosphere and
there will be no reduction in carbon % from the bearing.
REMEDIAL MEASURES (CONT..)
ENDOTHERMIC GAS
Basic Principles:
 To protect the material being processed from surface reaction; i.e., to be chemically inert.
 To allow the surface of the material being processed to change; i.e., to be chemically reactive.
 Endothermic atmosphere is prepared by reacting hydrocarbon gases like methane or propane
and air, in proportion such that there is enough proportion of oxygen to form hydrogen and
carbon monoxide without excess carbon dioxide and water vapors.
ENDOTHERMIC GAS
 Temperature : 1050oC
 Catalyst : Nickel
 2CH4 + O2 + 3.8N2  2CO + 4H2 + 3.8N2
 Chemistry of Endothermic Gas:
N2 45.1%
CO 19.6%
CO2 0.4%
H2 34.6%
CH4 0.3%
Dew Point +20/+50
(Air/Gas) ratio 2.6:1
REMEDIAL MEASURE (CONT..)
• QUENCHING CRACK :-
• Cracks formed by bearing parts in the Quenching process due to internal stress causes Quenching
Cracks.
• Quenching Crack is cause because Quenching heating temperature is too high or too fast cooling.
• If there’s defect in the surface of machining parts that can also lead to Quenching Cracks. Surface
decarburization carbide segregation, part quenching or tempering, non-metallic inclusions, previous
process (cold punching under stress, sharp edges, forging folding, etc.) are some of the other reasons
behind Quenching Cracks.
• This can cause failure of bearing.
• REMEDIES :-
• Using oil as quenchant and keeping quenching temperature around 90OC.
• Reliving internal stress before Heat Treating.
REMEDIAL MEASURES (CONT..)
• SOFT SPOT :-
• When hardness of surface is not enough it causes Soft Spots.
• Soft Spot causes because of insufficient heating and bad cooling.
• This leads to declinations of surface wear resistance and fatigue strength, also bring down hardness.
• REMEDIES :-
• Avoid formation of oxides
• Avoid Decarburization
CONCLUSION
With proper analysis and setting suitable process parameters for different
types of bearings, considering their thickness, weight and layer of loading by
controlling hardening temperature and cycle time according to requirement and best
possible results leads to decrease in oval deformation and other defects.
CONCLUSION
• Such parameters were set as follow:
REFRENCES
• www.abcbearings.com
• www.skf-nsk-bearings.com/news_con_1020.html
• www.brand-bearing.com/news/ykshownews1688.html
• www.nsk.com/services/basicknowledge/introduction.html
• http://snr-ntn.co.uk/INDUSTRY/de/de-de/file.cfm/02-SNR_Bearing_Technology.pdf
• http://thermalscienceapplication.asmedigitalcollection.asme.org/mobile/article.aspx?articleid=1485040
• Web.applied.com/site.cfm/Bearing_Failure_Analysis_operating_Conditions_Typically_Hold_key.cfm
• www.machineparts-blog.com/common-defects-of-bearing-after-heat-treatment/
• www.hellerbearings.com/news-1053.html
• Resources.alibaba.com/topic/800022682/Bearing_heat_treatment_what_are_the_common_quality_defect.htm
l
• www.google.com/paternts/US4023988
REFERENCES (CONT..)
• https://www.passle.net/post/102bwy3/bearing-parts-after-heat-treatment-of-the-common-quality-defects
• www.nmbtc.com/bearings/white-papers/what-is-a-ball-bearing/
• www.oilversteel.com/quench-cracking.htm
• www.intechopen.com/download/pdf/39388 - Deformation Reduction of Bearing Rings by Modification of
Heat Treating by Anton Panda, Jozef Jurko and Iveta Pandová
• www.heat-treat-doctor.com/documents/endothermic%20gas%20generators.pdf
• www.ims.it/ims/ims_spa/cmscontent.nsf/DocumentsByIDWeb/5YWJK7/$File/heat_treatment_defects_TS.pd
f

Weitere ähnliche Inhalte

Was ist angesagt?

Was ist angesagt? (20)

U3 p2 riser design
U3 p2 riser designU3 p2 riser design
U3 p2 riser design
 
Advanced casting and welding
Advanced casting and weldingAdvanced casting and welding
Advanced casting and welding
 
Centrifugal casting 1
Centrifugal casting 1Centrifugal casting 1
Centrifugal casting 1
 
Unit i classification of steel and cast iron microstructure
Unit i  classification of steel and cast iron microstructureUnit i  classification of steel and cast iron microstructure
Unit i classification of steel and cast iron microstructure
 
Heat treatment defects &and its remedies
Heat treatment defects &and its remediesHeat treatment defects &and its remedies
Heat treatment defects &and its remedies
 
Heat Treatment Process
Heat Treatment ProcessHeat Treatment Process
Heat Treatment Process
 
Thermal spray coating
Thermal spray coatingThermal spray coating
Thermal spray coating
 
Induction Hardening
Induction HardeningInduction Hardening
Induction Hardening
 
Pressure die casting
Pressure die castingPressure die casting
Pressure die casting
 
case hardening
case hardeningcase hardening
case hardening
 
Forging
ForgingForging
Forging
 
Heat treatment of steel
Heat treatment of steelHeat treatment of steel
Heat treatment of steel
 
Hot Rolling And cold rolling process
Hot Rolling And cold rolling processHot Rolling And cold rolling process
Hot Rolling And cold rolling process
 
hardening
hardeninghardening
hardening
 
Annealing , normalizing , quenching , martensitic transformation (1)
Annealing , normalizing , quenching , martensitic transformation (1)Annealing , normalizing , quenching , martensitic transformation (1)
Annealing , normalizing , quenching , martensitic transformation (1)
 
Centrifugal casting
Centrifugal    castingCentrifugal    casting
Centrifugal casting
 
TTT diagram
TTT diagramTTT diagram
TTT diagram
 
Nitriding and carbonitriding copy
Nitriding and carbonitriding   copyNitriding and carbonitriding   copy
Nitriding and carbonitriding copy
 
Manufacturing Processes
Manufacturing ProcessesManufacturing Processes
Manufacturing Processes
 
Surface hardening
Surface hardeningSurface hardening
Surface hardening
 

Andere mochten auch

Andere mochten auch (20)

Heat treatment : the best one
Heat treatment : the best oneHeat treatment : the best one
Heat treatment : the best one
 
Heat treatment process
Heat treatment processHeat treatment process
Heat treatment process
 
Heat Treatments
Heat TreatmentsHeat Treatments
Heat Treatments
 
Metal forming defects
Metal forming defectsMetal forming defects
Metal forming defects
 
Heat Treating Basics
Heat Treating BasicsHeat Treating Basics
Heat Treating Basics
 
Heat treatment
Heat treatmentHeat treatment
Heat treatment
 
Advanced Induction Heat Treatment Technologies and Design Methods
Advanced Induction Heat Treatment Technologies and Design MethodsAdvanced Induction Heat Treatment Technologies and Design Methods
Advanced Induction Heat Treatment Technologies and Design Methods
 
Kaizen FMEA (Uncompressed)
Kaizen FMEA (Uncompressed)Kaizen FMEA (Uncompressed)
Kaizen FMEA (Uncompressed)
 
Presentation quenching oil
Presentation  quenching oilPresentation  quenching oil
Presentation quenching oil
 
Heat Treatment
Heat TreatmentHeat Treatment
Heat Treatment
 
Ms chapter 2
Ms chapter 2Ms chapter 2
Ms chapter 2
 
Heat Treating: Selecting the Right Quenching Oil
Heat Treating: Selecting the Right Quenching OilHeat Treating: Selecting the Right Quenching Oil
Heat Treating: Selecting the Right Quenching Oil
 
Straightness of lines & surfaces
Straightness of lines & surfacesStraightness of lines & surfaces
Straightness of lines & surfaces
 
Diptongo, triptongo e hiato
Diptongo, triptongo e hiatoDiptongo, triptongo e hiato
Diptongo, triptongo e hiato
 
Bogie hearth furnance
Bogie hearth furnanceBogie hearth furnance
Bogie hearth furnance
 
Heat treatment course material
Heat treatment course materialHeat treatment course material
Heat treatment course material
 
Plastics injection molding
Plastics injection moldingPlastics injection molding
Plastics injection molding
 
17767705 heat-treatment-oct08
17767705 heat-treatment-oct0817767705 heat-treatment-oct08
17767705 heat-treatment-oct08
 
Lesson 6: Effects of Heat on Matter
Lesson 6: Effects of Heat on MatterLesson 6: Effects of Heat on Matter
Lesson 6: Effects of Heat on Matter
 
Shear box test
Shear box testShear box test
Shear box test
 

Ähnlich wie Heat Treatment Defects and their Remedies

Forming Welding & Heat treatment of ss equipment & components for Nuclear Rec...
Forming Welding & Heat treatment of ss equipment & components for Nuclear Rec...Forming Welding & Heat treatment of ss equipment & components for Nuclear Rec...
Forming Welding & Heat treatment of ss equipment & components for Nuclear Rec...Santosh Takale
 
EM-Unit-IV- case hardening
EM-Unit-IV- case hardeningEM-Unit-IV- case hardening
EM-Unit-IV- case hardeningMohanumar S
 
Introduction to Surface Treatments Case Hardening.pptx
Introduction to Surface Treatments Case Hardening.pptxIntroduction to Surface Treatments Case Hardening.pptx
Introduction to Surface Treatments Case Hardening.pptxprasannabhagwat3
 
Heat treatment 2 dr.sss
Heat treatment 2 dr.sssHeat treatment 2 dr.sss
Heat treatment 2 dr.ssssaravana kumar
 
Unit 4 ADVANCED NANO FINISHING PROCESSES
Unit  4 ADVANCED NANO FINISHING PROCESSESUnit  4 ADVANCED NANO FINISHING PROCESSES
Unit 4 ADVANCED NANO FINISHING PROCESSESShanmathyAR2
 
Thermochemical Processes
Thermochemical ProcessesThermochemical Processes
Thermochemical ProcessesSaiGayathri12
 
Selective Hardening process
Selective Hardening processSelective Hardening process
Selective Hardening processAbin Basil
 
CHEMICAL AND ELECTRO-CHEMICAL ENERGY BASED PROCESS
CHEMICAL AND ELECTRO-CHEMICAL ENERGY BASED PROCESSCHEMICAL AND ELECTRO-CHEMICAL ENERGY BASED PROCESS
CHEMICAL AND ELECTRO-CHEMICAL ENERGY BASED PROCESSravikumarmrk
 
UNIT 3.pptx
UNIT 3.pptxUNIT 3.pptx
UNIT 3.pptxKawinKit
 
Electro Chemical Machining Process
Electro Chemical Machining ProcessElectro Chemical Machining Process
Electro Chemical Machining ProcessPraveenManickam2
 
Chemical and electro chemical energy based processes
Chemical and electro chemical energy based processesChemical and electro chemical energy based processes
Chemical and electro chemical energy based processesRaja P
 
Exhaust Heat Management By Ceramic Coatings in Formula one
Exhaust Heat Management By Ceramic Coatings in Formula oneExhaust Heat Management By Ceramic Coatings in Formula one
Exhaust Heat Management By Ceramic Coatings in Formula oneAkheel Ahamed
 

Ähnlich wie Heat Treatment Defects and their Remedies (20)

Forming Welding & Heat treatment of ss equipment & components for Nuclear Rec...
Forming Welding & Heat treatment of ss equipment & components for Nuclear Rec...Forming Welding & Heat treatment of ss equipment & components for Nuclear Rec...
Forming Welding & Heat treatment of ss equipment & components for Nuclear Rec...
 
EM-Unit-IV- case hardening
EM-Unit-IV- case hardeningEM-Unit-IV- case hardening
EM-Unit-IV- case hardening
 
Case Hardening
Case HardeningCase Hardening
Case Hardening
 
Case hardening
Case hardeningCase hardening
Case hardening
 
Case hardening
Case hardeningCase hardening
Case hardening
 
2 case hardening
2 case hardening2 case hardening
2 case hardening
 
Introduction to Surface Treatments Case Hardening.pptx
Introduction to Surface Treatments Case Hardening.pptxIntroduction to Surface Treatments Case Hardening.pptx
Introduction to Surface Treatments Case Hardening.pptx
 
2 case hardening
2 case hardening2 case hardening
2 case hardening
 
Heat treatment 2 dr.sss
Heat treatment 2 dr.sssHeat treatment 2 dr.sss
Heat treatment 2 dr.sss
 
Unit 4 ADVANCED NANO FINISHING PROCESSES
Unit  4 ADVANCED NANO FINISHING PROCESSESUnit  4 ADVANCED NANO FINISHING PROCESSES
Unit 4 ADVANCED NANO FINISHING PROCESSES
 
Thermochemical Processes
Thermochemical ProcessesThermochemical Processes
Thermochemical Processes
 
Selective Hardening process
Selective Hardening processSelective Hardening process
Selective Hardening process
 
Unit 3
Unit 3Unit 3
Unit 3
 
Unit III
Unit IIIUnit III
Unit III
 
CHEMICAL AND ELECTRO-CHEMICAL ENERGY BASED PROCESS
CHEMICAL AND ELECTRO-CHEMICAL ENERGY BASED PROCESSCHEMICAL AND ELECTRO-CHEMICAL ENERGY BASED PROCESS
CHEMICAL AND ELECTRO-CHEMICAL ENERGY BASED PROCESS
 
Unit 3
Unit 3Unit 3
Unit 3
 
UNIT 3.pptx
UNIT 3.pptxUNIT 3.pptx
UNIT 3.pptx
 
Electro Chemical Machining Process
Electro Chemical Machining ProcessElectro Chemical Machining Process
Electro Chemical Machining Process
 
Chemical and electro chemical energy based processes
Chemical and electro chemical energy based processesChemical and electro chemical energy based processes
Chemical and electro chemical energy based processes
 
Exhaust Heat Management By Ceramic Coatings in Formula one
Exhaust Heat Management By Ceramic Coatings in Formula oneExhaust Heat Management By Ceramic Coatings in Formula one
Exhaust Heat Management By Ceramic Coatings in Formula one
 

Kürzlich hochgeladen

Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdf
Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdfRenewable Energy & Entrepreneurship Workshop_21Feb2024.pdf
Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdfodunowoeminence2019
 
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...Amil baba
 
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...Amil baba
 
GENERAL CONDITIONS FOR CONTRACTS OF CIVIL ENGINEERING WORKS
GENERAL CONDITIONS  FOR  CONTRACTS OF CIVIL ENGINEERING WORKS GENERAL CONDITIONS  FOR  CONTRACTS OF CIVIL ENGINEERING WORKS
GENERAL CONDITIONS FOR CONTRACTS OF CIVIL ENGINEERING WORKS Bahzad5
 
Phase noise transfer functions.pptx
Phase noise transfer      functions.pptxPhase noise transfer      functions.pptx
Phase noise transfer functions.pptxSaiGouthamSunkara
 
Basic Principle of Electrochemical Sensor
Basic Principle of  Electrochemical SensorBasic Principle of  Electrochemical Sensor
Basic Principle of Electrochemical SensorTanvir Moin
 
ChatGPT-and-Generative-AI-Landscape Working of generative ai search
ChatGPT-and-Generative-AI-Landscape Working of generative ai searchChatGPT-and-Generative-AI-Landscape Working of generative ai search
ChatGPT-and-Generative-AI-Landscape Working of generative ai searchrohitcse52
 
SUMMER TRAINING REPORT ON BUILDING CONSTRUCTION.docx
SUMMER TRAINING REPORT ON BUILDING CONSTRUCTION.docxSUMMER TRAINING REPORT ON BUILDING CONSTRUCTION.docx
SUMMER TRAINING REPORT ON BUILDING CONSTRUCTION.docxNaveenVerma126
 
A Seminar on Electric Vehicle Software Simulation
A Seminar on Electric Vehicle Software SimulationA Seminar on Electric Vehicle Software Simulation
A Seminar on Electric Vehicle Software SimulationMohsinKhanA
 
Mohs Scale of Hardness, Hardness Scale.pptx
Mohs Scale of Hardness, Hardness Scale.pptxMohs Scale of Hardness, Hardness Scale.pptx
Mohs Scale of Hardness, Hardness Scale.pptxKISHAN KUMAR
 
Modelling Guide for Timber Structures - FPInnovations
Modelling Guide for Timber Structures - FPInnovationsModelling Guide for Timber Structures - FPInnovations
Modelling Guide for Timber Structures - FPInnovationsYusuf Yıldız
 
Power System electrical and electronics .pptx
Power System electrical and electronics .pptxPower System electrical and electronics .pptx
Power System electrical and electronics .pptxMUKULKUMAR210
 
Technology Features of Apollo HDD Machine, Its Technical Specification with C...
Technology Features of Apollo HDD Machine, Its Technical Specification with C...Technology Features of Apollo HDD Machine, Its Technical Specification with C...
Technology Features of Apollo HDD Machine, Its Technical Specification with C...Apollo Techno Industries Pvt Ltd
 
nvidia AI-gtc 2024 partial slide deck.pptx
nvidia AI-gtc 2024 partial slide deck.pptxnvidia AI-gtc 2024 partial slide deck.pptx
nvidia AI-gtc 2024 partial slide deck.pptxjasonsedano2
 
Quasi-Stochastic Approximation: Algorithm Design Principles with Applications...
Quasi-Stochastic Approximation: Algorithm Design Principles with Applications...Quasi-Stochastic Approximation: Algorithm Design Principles with Applications...
Quasi-Stochastic Approximation: Algorithm Design Principles with Applications...Sean Meyn
 
cloud computing notes for anna university syllabus
cloud computing notes for anna university syllabuscloud computing notes for anna university syllabus
cloud computing notes for anna university syllabusViolet Violet
 
Nodal seismic construction requirements.pptx
Nodal seismic construction requirements.pptxNodal seismic construction requirements.pptx
Nodal seismic construction requirements.pptxwendy cai
 
How to Write a Good Scientific Paper.pdf
How to Write a Good Scientific Paper.pdfHow to Write a Good Scientific Paper.pdf
How to Write a Good Scientific Paper.pdfRedhwan Qasem Shaddad
 

Kürzlich hochgeladen (20)

Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdf
Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdfRenewable Energy & Entrepreneurship Workshop_21Feb2024.pdf
Renewable Energy & Entrepreneurship Workshop_21Feb2024.pdf
 
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...
Popular-NO1 Kala Jadu Expert Specialist In Germany Kala Jadu Expert Specialis...
 
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...
Best-NO1 Best Rohani Amil In Lahore Kala Ilam In Lahore Kala Jadu Amil In Lah...
 
GENERAL CONDITIONS FOR CONTRACTS OF CIVIL ENGINEERING WORKS
GENERAL CONDITIONS  FOR  CONTRACTS OF CIVIL ENGINEERING WORKS GENERAL CONDITIONS  FOR  CONTRACTS OF CIVIL ENGINEERING WORKS
GENERAL CONDITIONS FOR CONTRACTS OF CIVIL ENGINEERING WORKS
 
Phase noise transfer functions.pptx
Phase noise transfer      functions.pptxPhase noise transfer      functions.pptx
Phase noise transfer functions.pptx
 
Basic Principle of Electrochemical Sensor
Basic Principle of  Electrochemical SensorBasic Principle of  Electrochemical Sensor
Basic Principle of Electrochemical Sensor
 
ChatGPT-and-Generative-AI-Landscape Working of generative ai search
ChatGPT-and-Generative-AI-Landscape Working of generative ai searchChatGPT-and-Generative-AI-Landscape Working of generative ai search
ChatGPT-and-Generative-AI-Landscape Working of generative ai search
 
SUMMER TRAINING REPORT ON BUILDING CONSTRUCTION.docx
SUMMER TRAINING REPORT ON BUILDING CONSTRUCTION.docxSUMMER TRAINING REPORT ON BUILDING CONSTRUCTION.docx
SUMMER TRAINING REPORT ON BUILDING CONSTRUCTION.docx
 
A Seminar on Electric Vehicle Software Simulation
A Seminar on Electric Vehicle Software SimulationA Seminar on Electric Vehicle Software Simulation
A Seminar on Electric Vehicle Software Simulation
 
Mohs Scale of Hardness, Hardness Scale.pptx
Mohs Scale of Hardness, Hardness Scale.pptxMohs Scale of Hardness, Hardness Scale.pptx
Mohs Scale of Hardness, Hardness Scale.pptx
 
Présentation IIRB 2024 Chloe Dufrane.pdf
Présentation IIRB 2024 Chloe Dufrane.pdfPrésentation IIRB 2024 Chloe Dufrane.pdf
Présentation IIRB 2024 Chloe Dufrane.pdf
 
Modelling Guide for Timber Structures - FPInnovations
Modelling Guide for Timber Structures - FPInnovationsModelling Guide for Timber Structures - FPInnovations
Modelling Guide for Timber Structures - FPInnovations
 
Power System electrical and electronics .pptx
Power System electrical and electronics .pptxPower System electrical and electronics .pptx
Power System electrical and electronics .pptx
 
Technology Features of Apollo HDD Machine, Its Technical Specification with C...
Technology Features of Apollo HDD Machine, Its Technical Specification with C...Technology Features of Apollo HDD Machine, Its Technical Specification with C...
Technology Features of Apollo HDD Machine, Its Technical Specification with C...
 
nvidia AI-gtc 2024 partial slide deck.pptx
nvidia AI-gtc 2024 partial slide deck.pptxnvidia AI-gtc 2024 partial slide deck.pptx
nvidia AI-gtc 2024 partial slide deck.pptx
 
Quasi-Stochastic Approximation: Algorithm Design Principles with Applications...
Quasi-Stochastic Approximation: Algorithm Design Principles with Applications...Quasi-Stochastic Approximation: Algorithm Design Principles with Applications...
Quasi-Stochastic Approximation: Algorithm Design Principles with Applications...
 
cloud computing notes for anna university syllabus
cloud computing notes for anna university syllabuscloud computing notes for anna university syllabus
cloud computing notes for anna university syllabus
 
Présentation IIRB 2024 Marine Cordonnier.pdf
Présentation IIRB 2024 Marine Cordonnier.pdfPrésentation IIRB 2024 Marine Cordonnier.pdf
Présentation IIRB 2024 Marine Cordonnier.pdf
 
Nodal seismic construction requirements.pptx
Nodal seismic construction requirements.pptxNodal seismic construction requirements.pptx
Nodal seismic construction requirements.pptx
 
How to Write a Good Scientific Paper.pdf
How to Write a Good Scientific Paper.pdfHow to Write a Good Scientific Paper.pdf
How to Write a Good Scientific Paper.pdf
 

Heat Treatment Defects and their Remedies

  • 1. HEAT TREATMENT DEFECTS ON BEARING STEELS INTERNAL GUIDE :- Mrs MINAL DANI EXTERNAL GUIDE :- Mr SHASHIKANT JHA Mr VANRAJ RAJ RUPAPARAARUN(110130121004) MAKKA PALAK(110130121047) MIRAJ PATEL(110130121061)
  • 2. CONTENTS • INTRODUCTION • HEAT TREATMENT PROCESSES • HEAT TREATMENT DEFECTS IN BEARING • REMEDIAL MEASURES • CONCLUSION • REFERENCES
  • 3. INTODUCTION BEARINGS???? • Bearing is a machine element, which supports another moving machine element permitting the relative motion between the Contact surfaces with minimal friction. • Bearings application :- • Cars • Trains • Airplanes • Washing machines • Refrigerators • Air conditioners • Vacuum cleaners • Photocopy machines • Computers • Satellites
  • 4. INTRODUCTION BEARING PARTS BALL BEARING CAGE OUTER RING INNER RING ROLLING ELEMENT
  • 5. INTRODUCTION BEARING GRADES Bearing grade C% Si% Mn% P% Cr% Mo% Ni% S% AISI 52100 USA 0.95-1.1 0.15-0.35 0.5max 0.012max 1.3-1.6 0.08max 0.25max 0.25max 100Cr6 Germany 0.95-1.1 0.15-0.35 0.25-0.45 0.03 max 1.35-1.65 0.1 max - 0.2 max SUJ2 JAPAN 0.95-1.1 0.15-0.35 0.5 max 0.025 max 1.3-1.6 0.08 max 0.25 max 0.25 max GCr15 CHINA 0.95-1.05 0.15-0.35 0.25-0.45 0.027 max 1.4-1.65 0.1 max 0.23 max 0.2 max  At ABC we studied and experimented only on Bearing Grade AISI 52100.
  • 8. Wire coil ( raw material) ---- Made Roller. Cold Heating Operation Soft Tumbling Heat Treatment Grinding Honing Grading and Visual Inspection Bearing Assembly Austenizing (740oC – 800oC) Oil Quenching (90oC) Liquid Cooling (0oC - 5oC) Tempering (130oC – 160oC) Air Cooling
  • 9. Round bar (raw material)--- Made inner & outer ring. Hot forging Spherodized Annealing Turning Heat treatment Face/ OD Grinding Bore, Track & Flange grinding Honing & Etching Bearing assembly Austenizing (740oC – 800oC) Oil Quenching (90oC) Liquid Cooling (0oC - 5oC) Tempering (130oC – 160oC) Air Cooling
  • 11. HEAT TREATMENT PROCESS SPHEROIDIZED ANNEALING :- • Spheroidization is achieved by holding the metal for a prolonged period at austenizing temperature and cooling at a very slow rate by along with appropriate soaking time. • Spheroidize annealing is done to form spheroids of carbon to improve machinability and prepare the metal structure for hardening. • Temperature: up to 860OC • Cycle time: about 48 to 54 hours with slow furnace cooling along with intervals of socking time. QUENCHING :- • Cooling a metal at a rapid rate. • Used to produce a martensitic transformation. • Often produce a harder metal in ferrous, softer than normal in non ferrous. • Metal heated above the upper critical temperature and then quickly cooled. • Quenchant : Ferro-quench oil. • Temperature : 90OC • Cycle time : 8 mins
  • 12. HEAT TREATMENT PROCESS (CONT..) INDUCTION HARDENING :- • A surface hardening technique. • Surface of the metal is heated very quickly, using a no-contact method. • Martensitic transformation at the surface, leaving the underlying metal unchanged after quenching. • Creates a very hard, wear resistant surface maintaining toughness in the majority of the object. FLAME HARDENING :- • Used to harden only a portion of a metal. • Only a portion of the metal is heated before quenching. • Often produces an extremely brittle zone between the heated metal and the unheated metal, as cooling at the edge of this heat affected zone is extremely rapid.
  • 13. HEAT TREATMENT PROCESS (CONT..) NITRIDING :- • Creates a case hardened surface by diffusing nitrogen into the surface of a metal. • Commonly used on low-carbon, low-alloy steels, medium and high-carbon steels, titanium, aluminium and molybdenum. TEMPERING :- • Usually performed after hardening, reduce some of the excess hardness. • Heating the metal at temperature below the critical temperature for a certain period of time. • Air cooling. • It controls brittleness caused after quenching and retain its strength and toughness. • Produces martensitic + austenitic structure. • Temperature : 175OC – 210OC • Cycle time : 3 hours
  • 14. MECHANICAL TESTING Hardness Testing :- • Before Heat Treatment : 25 – 30 BHN • After Quenching : 64 – 65 BHN • After Tempering : 61 – 62 BHN Oval Distortion Testing :- • Final Turning Ring(FTR) : 10 – 30µ • Heat Treated Ring(HTR) : <150µ • Total material of ring after removing ovality : >250µ
  • 15. HEAT TREATMENT DEFECTS • Less Supply Of Endo Gas • Improper Oil Curtain • Incoming (Raw Material) Problem • Power Failure • Oxygen In F/C. (Disturb Inert Atmosphere) SURFACE DECARBURIZATION :- • Thermal gradient in the component • Over heating • Non-uniform cooling • Severe quenching • Improper tempering • Design defects QUENCHING CRACKS :-
  • 18. HEAT TREATMENT DEFETS (CONT..) • Furnace Atmosphere • Poor Quality Quenching Medium • Dirty Component Surface • Defective Initial Microstructure SOFT SPOT :- • Poor Quality Quenching Medium • Thermal Gradient before Quenching • Section Thickness Variation of the Components • Component’s Shape, Dimensions & Position During Quenching • Agitation of Quenching Medium • Initial Microstructure of Material HEAT TREATMENT DEFORMATION :-
  • 21. HEAT TREATMENT DEFECTS (CONT..) • Non uniform Microstructure • Unwanted Phase • Grain Growth • Grain Boundary Precipitation • Retained Austenite • Decarburization MICRO STRUCTURAL DEFECTS :- • Lower & Higher Hardening Temperature. • Heater Failure/Power Failure/Disturb Inert Atmosphere. • Less Soaking Time During Hardening LOW HARDNESS :- • Lower Soaking Time • Lower Tempering Temperature HIGH HARDNESS :-
  • 23. REMEDIAL MEASURES Heat Treatment Deformation  Residual stresses that cause shape change when they exceed material yield strength. This occurs on heating when the strength properties decline.  Stresses caused by differential expansion due to thermal gradients. These stresses increase with the thermal gradient and cause plastic deformation as the yield strength is exceeded.  Volume changes due to transformational phase change. These volume changes are contained as residual stress systems until the yield strength is exceeded.
  • 24. REMEDIAL MEASURES OVALITY • Ovality is a certain type of circularity deviation. Ovality results from non-symmetrical distribution of internal tensions before hardening and uneven heating and cooling. • Devices using very accurate rotational tables or spindles are used to measure circularity. The axis of the component is the measuring base in this method. The measuring device ensures very high accuracy, often better than 1 μm. • Ovality is checked after Quenching. A special diameter gauge (Figure) that included a dial deviation meter was used to measure ovality. • Ovality was measured on 10-20 rings so that an ovality deviation was recorded after each rotation. The following procedure was applied : • A bearing ring was inserted into the gauge and was rotated manually. • A value was read from the deviation meter after each rotation. • If the deviation was higher than 150 μm, the ring being measured was discarded. It did not meet quality criteria and could not be passed on for subsequent hard machining.
  • 26. REMEDIAL MEASURE (CONT..) 1. Heat Treatment Deformation: • Preheating of bearing prior to heat treatment. • Reduce hardening temperature and slow heating. • Keeping 5 zone in hardening so that it can achieve required temperature at desired cycle time. • Rate of cooling after hardening should be less. • Bolting the ring and re-tempering.
  • 27. REMEDIAL MEASURES (CONT..) 2. Surface Decarburization : • By controlling furnace atmosphere, i.e., by generating “Endothermic Gas(Endo Gas)” and producing it inside furnace and controlling its carbon potential. • Carbon potential : 0.94% – 0.97% • This will allow carbon inside bearing to stay in equilibrium with the atmosphere and there will be no reduction in carbon % from the bearing.
  • 28. REMEDIAL MEASURES (CONT..) ENDOTHERMIC GAS Basic Principles:  To protect the material being processed from surface reaction; i.e., to be chemically inert.  To allow the surface of the material being processed to change; i.e., to be chemically reactive.  Endothermic atmosphere is prepared by reacting hydrocarbon gases like methane or propane and air, in proportion such that there is enough proportion of oxygen to form hydrogen and carbon monoxide without excess carbon dioxide and water vapors.
  • 29. ENDOTHERMIC GAS  Temperature : 1050oC  Catalyst : Nickel  2CH4 + O2 + 3.8N2  2CO + 4H2 + 3.8N2  Chemistry of Endothermic Gas: N2 45.1% CO 19.6% CO2 0.4% H2 34.6% CH4 0.3% Dew Point +20/+50 (Air/Gas) ratio 2.6:1
  • 30. REMEDIAL MEASURE (CONT..) • QUENCHING CRACK :- • Cracks formed by bearing parts in the Quenching process due to internal stress causes Quenching Cracks. • Quenching Crack is cause because Quenching heating temperature is too high or too fast cooling. • If there’s defect in the surface of machining parts that can also lead to Quenching Cracks. Surface decarburization carbide segregation, part quenching or tempering, non-metallic inclusions, previous process (cold punching under stress, sharp edges, forging folding, etc.) are some of the other reasons behind Quenching Cracks. • This can cause failure of bearing. • REMEDIES :- • Using oil as quenchant and keeping quenching temperature around 90OC. • Reliving internal stress before Heat Treating.
  • 31. REMEDIAL MEASURES (CONT..) • SOFT SPOT :- • When hardness of surface is not enough it causes Soft Spots. • Soft Spot causes because of insufficient heating and bad cooling. • This leads to declinations of surface wear resistance and fatigue strength, also bring down hardness. • REMEDIES :- • Avoid formation of oxides • Avoid Decarburization
  • 32. CONCLUSION With proper analysis and setting suitable process parameters for different types of bearings, considering their thickness, weight and layer of loading by controlling hardening temperature and cycle time according to requirement and best possible results leads to decrease in oval deformation and other defects.
  • 33. CONCLUSION • Such parameters were set as follow:
  • 34. REFRENCES • www.abcbearings.com • www.skf-nsk-bearings.com/news_con_1020.html • www.brand-bearing.com/news/ykshownews1688.html • www.nsk.com/services/basicknowledge/introduction.html • http://snr-ntn.co.uk/INDUSTRY/de/de-de/file.cfm/02-SNR_Bearing_Technology.pdf • http://thermalscienceapplication.asmedigitalcollection.asme.org/mobile/article.aspx?articleid=1485040 • Web.applied.com/site.cfm/Bearing_Failure_Analysis_operating_Conditions_Typically_Hold_key.cfm • www.machineparts-blog.com/common-defects-of-bearing-after-heat-treatment/ • www.hellerbearings.com/news-1053.html • Resources.alibaba.com/topic/800022682/Bearing_heat_treatment_what_are_the_common_quality_defect.htm l • www.google.com/paternts/US4023988
  • 35. REFERENCES (CONT..) • https://www.passle.net/post/102bwy3/bearing-parts-after-heat-treatment-of-the-common-quality-defects • www.nmbtc.com/bearings/white-papers/what-is-a-ball-bearing/ • www.oilversteel.com/quench-cracking.htm • www.intechopen.com/download/pdf/39388 - Deformation Reduction of Bearing Rings by Modification of Heat Treating by Anton Panda, Jozef Jurko and Iveta Pandová • www.heat-treat-doctor.com/documents/endothermic%20gas%20generators.pdf • www.ims.it/ims/ims_spa/cmscontent.nsf/DocumentsByIDWeb/5YWJK7/$File/heat_treatment_defects_TS.pd f