Precision Case Hardening for High-Volume Production with Distortion Control

1. 20171021
Production with Distortion Control
Precision Case Hardening for High-Volume

2. AN ADVANCED TECHNOLOGY SOLUTION
FOR MANUFACTURING
The UniCase Master ®
(Source: SECO/WARWICK)

3. BENEFITS IN COMPARISON TO TRADITIONAL ATMOSPHERE TECHNOLOGY
/ In-line manufacturing
/ Elimination batch material handling costs & time
/ Enhanced process precision, quality & repeatability
/ Less overall distortion
/ Improved distortion control
/ High productivity, fast throughput
/ Superior surface quality
/ No intergranular oxidation (IGO)
/ Reduced utility consumption
/ No quenching oil and post-washing
/ Safety, no open flame, no risk of fire or explosion
/ Clean, environmentally friendly process
/ System flexibility & adaptability
A few of the many UniCase Master ® benefits to industry include:
(Source: SECO/WARWICK)

4. CASE HARDENING BY CARBURIZING
/ Carburizing is a thermo-chemical process in which carbon is
introduced into the surface of a component part followed by
rapid quenching, which results in a hard and wear resistant
surface and a soft, ductile core.
/ Used in applications requiring enhanced surface properties
(wear, abrasion) are needed such as in power transmission
applications for drive system components such as gears,
shafts, and bearings to name a few.
/ A typical requirement for case hardening is:
Surface hardness 58 - 62 HRC
Effective Case Depth 0,4 – 2 mm at 550 HV (52,5 HRC)
0.015 – 0.08” at 50 HRC (513 HV)
(Source: SECO/WARWICK;
www.shanthigears.com/product
s/loose-gears/ )

5. TRADITIONAL TECHNOLOGY SOLUTIONS -
/ Endothermic atmosphere or
nitrogen/methanol carburizing
/ Quenching in oil
/ Large footprint installations
(Source: SECO/WARWICK)
ATHMOSPERE FURNACES & SALT BATH EQUIPMENT

6. TRADITIONAL HEAT TREATMENT
/ Each piece in the load is exposed to a
different heat treatment, depending on
its position in the batch in terms of
temperature, carburizing case depth and
hardness after quenching.
The result is high variability and poor
repeatability.
/ Quenching is directional (2D)
creating temperature gradients and a
large amount of thermal distortion.
The result is a large amount of thermal
distortion.
(Source: SECO/WARWICK)
BATCH EXAMPLES

7. TRADITIONAL TECHNOLOGY
/ Uncontrolled distortion and poor repeatability
/ High material handling costs
Low process and operation flexibility
Inability to monitor single pieces
Intergranular oxidation
/ Cost of fixtures
Cost of maintenance
Costs of waste neutralization
Risk of fire and explosion
Environmental issues
(Source: SECO/WARWICK)
DISADVANTAGES

8. MODERN TECHNOLOGY SOLUTION
(Source: SECO/WARWICK)
VACUUM FURNACES FOR CASE HARDENING (LPC+HPGQ/OIL)

9. LOW PRESSURE CARBURIZING + HIGH PRESSURE GAS QUENCH
/ More accurate process results re: uniformity & quality
/ Less quenching distortion
/ Fast, high temperature carburizing
/ No intergranular oxidation
/ Ideal surface quality
/ Reduction of energy and process gases consumption & emission
/ Elimination of oil, washer and washing fluids
/ Safe, no open flame, no risk of fire or explosion
/ Clean and environmentally friendly
(Source: SECO/WARWICK)

10. COMMON PARTS HANDLING - A BATCH SOLUTION
Result = function of [time (t), temperature (T), atmosphere (C), quenching (Q)]
t(2), T(2), C(2), Q(2)
t(3), T(3), C(3), Q(3)
t(1), T(1), C(1), Q(1)
t(1) ≠ t(2) ≠ t(3)
T(1) ≠ T(2) ≠ T(3)
C(1) ≠ C(2) ≠ C(3)
Q(1) ≠ Q(2) ≠ Q(3)
ECD(1) ≠ ECD(2) ≠ ECD(3)
0,6 – 1,1 mm
0.020 – 0.040”
(Wide case depth
variation / tolerances)

11. DISTORTION – UNI-DIRECTIONAL COOLING
Directional cooling ≠ even gas stream
Uniform gas stream ≠ uniform cooling
Uniform cooling ≠ lower distortion
BATCH
GAS
INFLOW
GAS
OUTFLOW
ONE SIDE COOLING
Even gas flow does not guarantee uniform cooling of part
Uniform cooling does not mean lower distortion
Directional cooling does not ensure even gas flow
in the entire working space
(Source: SECO/WARWICK)

12. DISTORTION – UNI-DIRECTIONAL COOLING
TEMPERATURE GRADIENT = DISTORTION
NITROGEN 20 BAR, 15 m/s
GAS FLOW: TOP TO BOTTOM
ΔT ≈ 500oC
ΔT ≈ 930oF
(Source: SECO/WARWICK)

13. IS THE BATCH HANDLING THE ONLY SYSTEM ?
3
(Source: SECO/WARWICK)

14. Precision Case Hardening
using a Single Piece Flow with
Low Pressure Carburizing & 4D Quenching®
2017

15. LEAN MANUFACTURING
Heat treatment integration into continuous manufacturing production lines
(Source: SECO/WARWICK)

16. PROCESS FLOWCHART – 100% TRACEABILITY
GREEN PARTS
PRE-WASH
INDIVIDUAL PART IDENTIFICATION
PRECISION CASE HARDENING
BY LOW PRESSURE CARBURIZING &
4D QUENCHING®
POST COOLING/FREEZING
TEMPERING
POST COOLING
NON-DESTRUCTIVE TESTING NEXT STEP
REVOLUTIONARYINNOVATION
UniCaseMaster®System
SINGLEPIECEFLOW
(Source: SECO/WARWICK)

17. UniCase Master ® – INSTALLATION OVERVIEW
H3,5m(11,5ft)
(Source: SECO/WARWICK)
CONSUMTION:
• Power 150 kW
• Nitrogen 20 kg/h
• Acetylene 30 dm3/min
• Water 10 m3/h

18. 8
• Gear dia. 200 mm (8.0”)
• Height 50 mm (2.0”)
• Gear mass 4 kg (9 lbs)
• Number of positions 15 (per process chamber)
• Tact time 30 sec.
• Temperature 1100oC (2000oF)
• Uniformity +/- 5oC (10oF)
• LPC FineCarb®, PreNitLPC®
• Quenching up to 10 bar N2
UniCase Master ® – SPECIFICATION
(Source: SECO/WARWICK)

19. UniCase Master ®– SINGLE-PIECE FLOW – HEAT-UP
IN
LPCDIFFUSION
ELEVATOR
4D QUENCHING ®
ELEVATOR
HEAT-UP
(Source: SECO/WARWICK)

20. HEAT-UP IN HEAT-UP CHAMBER (1)
Heating curve by radiation, CFD simulation for a single gear,
dia. 190 mm / 7.5” , 3,0 kg / 6.6 lbs, ε = 0,35
(Source: SECO/WARWICK)

21. UniCase Master ®– SINGLE-PIECE FLOW – LPC
IN
ELEVATOR
4D QUENCHING ®
ELEVATOR
HEAT-UP
LPCDIFFUSION
(Source: SECO/WARWICK)

22. UniCase Master ®– SINGLE-PIECE FLOW – DIFFUSION
IN
LPC
ELEVATOR
4D QUENCHING ®
ELEVATOR
HEAT-UP
LPCDIFFUSION
(Source: SECO/WARWICK)

23. FINAL CARBON PROFILE AFTER DIFFUSION
30 min total process time (LPC and diffusion at 1040oC / 1900oF)
(Source: SECO/WARWICK)

24. UniCase Master ® – SINGLE-PIECE FLOW - QUENCHING
IN OUT
ELEVATOR
4D QUENCHING ®
ELEVATOR
HEAT-UP
ELEVATOR
LPCDIFFUSION
(Source: SECO/WARWICK)

25. UniCase Master ® – 4D QUENCHING® – UNIFORM & EFFICIENT
4D = 3D (cooling gas is delivered by nozzles from all sides)
+ 1D as the quenched part rotates
TRANSFER TO QUENCH
/ Stationary
/ Rotation (rpm and direction)
/ Oscillation (variable angle)
/ Time depend gas flow
Controlled
Cooling
00:00:00,000START QUENCH
2 SECONDS
5 SECONDS
9 SECONDS
(<500ºC)
Minimal
Distortion
Powerful cooling in 10 bar nitrogen –
as fast as oil quenching
Heat transfer – 2,000 W/K-m2
Oil He
(Source: SECO/WARWICK)

26. CARBURIZING UNIFORMITY
Max 0,595 g
Min 0,583 g
2 % PRECISION
Extremely uniform carbon absorption within all parts
(Source: SECO/WARWICK)
Mass increase by carbon absorption in gears
1050ºC (1925ºF) ECD 0.6 mm (0.024”)

27. CARBURIZING PRECISION
0,8 mm + 0,5 mm
0.032” + 0.20”
requirement
Target 0,90 mm
0.035”
Result 0,90±0,03mm
0.035” ± 0.001”
Microhardness – Active Flank
(Source: SECO/WARWICK)

28. 0
10
20
30
40
50
60
70
80
90
100
3D ANALYSIS
OF RING GEAR TOOTH FORM
TRDITIONAL BATCH
GAS QUENCHING
Toothformdistortion[%]
UniCase Master ®DISTORTION
UniCase Master ®
INITIAL PROCESS
UniCase Master®
OPTIMIZED PROCESS
/ 3-5 times less distortion in
comparison to batch HPGQ technology
green parts
case hardened parts
DIA ~180 mm
~7,1”
(Source: SECO/WARWICK)

29. DISTORTION
/ 2-4 times less distortion (size change and variation)
compared to vacuum batch oil quenching
UniCase Master ®
200 mm (8”)
120
100
80
60
40
20
0
Distortion[µm]
(Source: SECO/WARWICK)

30. DISTORTION
0
10
20
30
40
50
60
70
80
90
100
INTERNAL GEAR DISTORTION
Radial Run-OutAxial Run-Out Fp (Sum of Left & Right)
Cumulative Pitch Deviationn
Parallelism
Distortion[µm]
UniCase Master ®
green parts
case hardened parts
Class 7
Class 8
Class 9
Class 7
Class 8
DIA ~160 mm
~6,3”
/ 2-5 times less distortion in
comparison to vacuum batch oil quenching
(Source: SECO/WARWICK)

31. UniCase Master ® – PRODUCTIVITY
/ Frequency cycle 60 s
/ Effective case depth 0,6 mm /0.024”
/ Steel grade 20MnCr5/8620
/ Process timing 15 x 60 s
- Heating up 15 min
- LPC 15 min
- Diffusion 15 min
0.5 million/year
Gear Diameter 8.0” / 200 mm
Time Gear
Production
1 minute 1
1 hour 60
8 hours 480
24 hours 1,440
5 days 7,200
1 week 10,080
30 days 43,200
6,500 hours 390,000
7,000 hours 420,000
7,500 hours 450,000
8,000 hours 480,000
1 year 525,600
(Source: SECO/WARWICK)

32. / Frequency cycle 30 s
/ Effective case depth 0,6 mm /0.024”
/ Steel grade 20MnCr5/8620
/ Process timing 30 x 30 s
- Heating up 15 min
- LPC 15 min
- Diffusion 15 min
UniCase Master ® – PRODUCTIVITY
1 million/year
Gear Diameter 4.0” / 100 mm
Time Gear
Production
1 minute 2
1 hour 120
8 hours 960
24 hours 2,880
5 days 14,400
1 week 20,160
30 days 86,400
6,500 hours 780,000
7,000 hours 840,000
7,500 hours 900,000
8,000 hours 960,000
1 year 1,051,200
(Source: SECO/WARWICK)

33. THROUGHPUT INCREASE
x4
x16
(Source: SECO/WARWICK)

34. FLEXIBILITY & ADAPTABILITY (MULTIPLE CONFIGURATIONS
/ PROCESSES)
Re-sizing
Multi-chamber &
multi-position
LPC & HPGQ
Hardening, LPC,
Annealing, Brazing, etc.
Single-chamber &
multi-position
Multi-chamber &
single-position
Single-chamber &
single-position
Technology, process,
throughput
(Source: SECO/WARWICK)

35. UniCase Master ® – INNOVATION IN CASE HARDENING
/ Lean manufacturing / High throughput / Low cost
• 100% integration into continuous production lines
• Zero cost of heat treatment fixtures
• Zero cost of logistics involving material handling
/ Single-piece flow
• 10 times improvement in precision & repeatability of results
• 100% traceability, individual part monitoring and reporting
• 100% single part in-line testing after case hardening
/ 4D Quenching®
• 2 – 4 times less distortion (size change)
• 2 – 4 times less distortional variation
• 2 – 4 times less hard machining time
• Elimination of many post-machining operations
/ Low Pressure Carburizing / High Pressure Gas Quench
• Elimination of IGO / IGA
• Elimination of fire and explosion hazards
• Clean & environmentally friendly production
/ System flexibility & adaptability
• Operational & technological & process flexibility
• Modularity
• Multiple configurations (resizing)
(Source: SECO/WARWICK)

36. UniCase Master ® – REVOLUTION IN CASE HARDENING
Lean Manufacturing – Single-Piece Flow
Distortion Control – 4D Quenching®
Flexible & Modular Configuration
Industry 4.0
(Source: SECO/WARWICK)

37. THANK YOU
SECO/WARWICK S.A.
8 SOBIESKIEGO STR.,
66-200 ŚWIEBODZIN, POLAND
WWW.SECOWARWICK.COM
Marcin PRZYGOŃSKI
Sales Manager / Vacuum Furnaces Division
Mob: +48 519 051 635
E-mail: Marcin.Przygonski@secowarwick.com
Web: www.secowarwick.com