Feb 28 2013
Topics Covered
Introduction
Chemical Composition
Mechanical Properties
Other Designations
Manufacturing Process
Applications
Introduction
Grade 202 stainless steel is a type of Cr-Ni-Mn stainless with similar properties to A240/SUS 302 stainless steel. The toughness of grade 202 at low temperatures is excellent.
It is one of the most widely used precipitation hardening grades, and possesses good corrosion resistance, toughness, high harness, and strength.
The following datasheet provides an overview of grade 202 B stainless steel.
Chemical Composition
The chemical composition of grade 202 stainless steel is outlined in the following table.
|
Element |
Content (%) |
|
Iron, Fe |
68 |
|
Chromium, Cr |
17- 19 |
|
Manganese, Mn |
7.50-10 |
|
Nickel, Ni |
4-6 |
|
Silicon, Si |
≤ 1 |
|
Nitrogen, N |
≤ 0.25 |
|
Carbon, C |
≤ 0.15 |
|
Phosphorous, P |
≤ 0.060 |
|
Sulfur, S |
≤ 0.030 |
Mechanical Properties
The mechanical properties of grade 202 stainless steel are displayed in the following table.
|
Properties |
Metric |
Imperial |
|
Tensile strength |
515 MPa |
74694 psi |
|
Yield strength |
275 MPa |
39900 psi |
|
Elastic modulus |
207 GPa |
30000 ksi |
|
Poisson's ratio |
0.27-0.30 |
0.27-0.30 |
|
Elongation at break |
40% |
40% |
Other Designations
Equivalent materials to grade 202 stainless steel are given below:
|
ASTM A276 |
ASTM A314 |
ASTM A412 |
ASTM A429 |
|
ASTM A473 |
ASTM A666 |
FED QQ-S-763 |
FED QQ-S-766 |
|
FED STD-66 |
SAE 30202 |
SAE J405 (30202) |
|
Manufacturing Process
The machinability of grade 202 stainless steel produces long, gummy chips. Machining can also be performed in the annealed condition. For heat treatment, the material has to be soaked at 1038°C (1900°F) for 30 min and cooled below 16°C (60°F) for full martensite transformation. The material can be welded by common fusion and resistance methods; however, this steel should not be joined using oxyacetylene welding method. The recommended filler metal is AWS E/ER630. Forging can be done by pre-soaking for 1 h at 1177°C (2150°F). Forging below 1010°C (1850°F) is not advisable.
Applications
The grade 202 steel can be made into plates, sheets, and coils to be used in the following:
-
Restaurant equipment
-
Cooking utensils
-
Sinks
-
Automotive trim
-
Architectural applications such as windows and doors
-
Railway cars
-
Trailers
-
Hose clamps.