410 STAINLESS STEEL
410 Stainless Steel offers both outstanding corrosion resistance and exceptional wear resistance. To obtain the best possible strength and wear resistance, oil quench type 410 Stainless Steel at a temperature between 1800° F and 1950° F. Due to the advantages of heat and corrosion resistance, type 410 is most often used in cutlery, valve components, gas and steam turbine buckets and blades, kitchen utensils, and screens. 410 Stainless Steel is weldable but it is recommended to preheat it first and to anneal it after welding. When hot working with stainless steel type 410, use temperatures between 2000° F and 2200° F. Alloy 410 Stainless Steel can also be cold formed utilizing most standard methods
420 STAINLESS STEEL
Type 420 Stainless Steel provides both outstanding corrosion resistance and exceptional wear resistance. To obtain the best possible strength and wear resistance, oil quench alloy 420 at a temperature between 1800° F and 1950° F. Alloy 420 Stainless Steel is commonly used in dental and surgical instruments, cutlery, plastic molds, pump shafts, steel balls, and numerous hand tools. Because of its air hardening properties, type 420 Stainless Steel is not often welded, although, it is possible. When welding with stainless steel type 420, preheat the steel to a temperature between 300° F and 400° F. After welding, temper the work piece at temperature for two hours. When hot working, it is recommended to gradually raise the temperature to 1400° F and then gradually raise the temperature to anywhere from 2000° F to 2200° F. While working, avoid letting the work temperature drop below 1600° F by frequently reheating the steel. To prevent cracking, furnace cool the work piece slowly after working. Any extreme cold forming will cause alloy 420 Stainless Steel to crack, but it can endure minor cold work.
Typical Analysis
|
Grade |
Carbon |
Manganese |
Phosphorous |
Sulphur |
Silicon |
Chromium |
|
AISI 410 |
0.10% |
0.80% |
0.030% |
0.010% |
0.20% |
11.5% |
|
0.14% |
0.90% |
max |
max |
0.40% |
12.5% |
|
|
AISI 420 |
0.17% |
0.70% |
0.030% |
0.010% |
0.20% |
12.00% |
|
0.20% |
0.80% |
max |
max |
0.40% |
13.00% |
Applications: Capability of hardening and tempering makes this material suitable for applications like- Shafts, valve bodies requiring corrosion and heat resistance with a combination of strength and fatigue.
AISI 410/420- Supply condition -Ingot route material hot rolled to sizes up to 160 mm dia, followed by hardening and tempering. Peeling is done as per customer requirements. Blocks are used by Forging Industries for forging the components desirous of corrosion and heat resistance in the applications up to 815 °C.
Sections greater than 160mm dia are forged from bigger ingots (3T to 13T weight). Forging is done either at Bharat Forge or other forging units. Heat Treatment:
Normalizing : Not recommended.
Annealing : Can be Process/Full/Isothermal annealed.
|
Heat Treatment |
GradeAISI |
Temp °C |
Hardness |
Remarks |
|
Process Anneal |
410 |
650/760 |
86/92 HRB |
Controlled atmosphere |
|
420 |
675/760 |
94/97 HRB |
||
|
Isothermal |
410 |
830/885 |
85 HRB |
Slow cooling to 705 °C Hold for 6 hrs |
|
420 |
830/885 |
95 HRB |
Slow cool to 705 °C Hold for 2 hrs | |
|
Full Anneal |
410 |
830/885 |
75/85 HRB |
Controlled atmosphere Slow cool @ 17/23 °C/hr to 595 °C for severe forming applications |
|
420 |
|
86/95HRB |
||
|
Hardening |
410 |
925/1010 |
375/415HB |
As quench hardness |
|
420 |
980/1065 |
448/564HB |
As quench hardness | |
|
Tempering |
410 |
205/370 |
38/47HRC |
Stabilize at –76 to -195 °C |
|
420 |
205/370 |
48/56HRC |
Stabilize at –74 °C | |
|
Nitriding |
410 |
Not recommended |
||
|
420 |
Can be to 0.203 mm max case depth. |
|||
RECOMMENDED PROCESSING SEQUENCE:
- Forging
- Annealing
- Rough machine
- Stress relieve
- Finish machine
- Preheat
- Austenitise
- Oil quench
- Stabilize optional
- Temper (double temper for better impact properties)
- Final grinding
- Nitriding-if required