The 201 grade of stainless steel is composed of elements such as nitrogen, manganese, and nickel. Due to its lower content of nickel, this grade is considered affordable compared to other stainless steel grade. However, this material is difficult to form, weld, or work to produce different parts.
SS201 has a non-magnetic property. Therefore, it belongs to the austenitic stainless steel family. With its superior mechanical properties, these materials can provide high performance in applications that require cold work or annealed conditions.
History and Development
The development of 200 series grades of stainless steel takes place in the United States when the supply of 300 SS series during the 2nd world war becomes insufficient due to strictly nickel controlling. To solve the 300 series scarcity, stainless steel should be produced with low nickel content. Hence, the development of new austenitic stainless steel 201 grade.
Different Properties of Stainless Steel 201
Mechanical
For Annealed
| Yield Strength | Min. 45ksi |
| Tensile Strength | Min. 95ksi |
| Elongation | Min. 40% |
| Hardness | Max. 100(Rb) |
For Cold Work
| Condition | Strength | Elongation | ||
| Yield | Tensile | <0.015 in | ≥0.015 in. | |
| Full Hard | Min. 140ksi | Min.185ksi | 8% | 9% |
| 1/2 Hard | Min.110ksi | Min.150ksi | 15% | 18% |
| 3/4 Hard | Min.135ksi | Min.175ksi | 10% | 12% |
| ¼ Hard | Min.75ksi | Min.125% | 25% | 25% |
Physical
| Density | 0.283 lb/in3 |
| Elasticity Modulus | 28.6×106psi |
| Thermal Coefficient Expansion | 9.2×10–6 68-212˚F, /˚F |
| Thermal Conductivity | 9.4Btu/ft hr ˚F |
| Specific Heat | 0.12Btu/lb hr ˚F |
| Electrical Resistivity | 27.0Ω-in |
Chemical Composition
| C | 0.15% |
| Cr | 16 to 18% |
| Ni | 3.5 to 5.5% |
| Mn | 5.50 to 7.50% |
| Si | 1% |
| N | 0.25% |
| P | 0.060% |
| S | 0.030% |
Standards for 201 Stainless Steel
- ASME SA240
- ASTM A666
- ASTM A240
- SAE J045
- ASTM A213
- QQ S766
- ASTM A412
- SAE 30201
- ASTM A276
Comes in a Wide Range of Forms
In Coil Form
- Ribbon
- Strip
- Foil
In Wire Form
- Square
- Profile
- Flat
- Round
Different Characteristics of SS201
- Ideal alternative to stainless steel 304
- Lesser corrosion resistance in chemical environment
- Comes with a higher yield strength
- Higher toughness
Processing and Fabrication
Annealing
The 201 stainless steel can be annealed in a temperature ranging from 1850⁰F up to 2000⁰F (1010⁰C to 1093⁰C). Scaling of the material can be avoided if the temperature used for annealing will not exceed over 2000⁰F. Also, carbide crystallization can be prevented when it is cooled rapidly.
Forming
A wide range of forming methods can be used for stainless steel 201. However, it will return to its original shape when bended because of its high spring back nature.
Hot Working
This grade of stainless steel can undergo hot work processing with temperature ranges from 2100 to 2250⁰F.
Welding
Any conventional welding methods are suitable for stainless steel 201 using a filler metal. However, the heat affected zone of the welded material is susceptible to corrosion.
Heat Treatment
201 stainless steel cannot achieve hardness through heat treatment.
Cold Forming
These materials are highly cold formable. It can also be used for different processing including heading, stamping, and drawing.
Surface Finishes and Treatments
- For ribbon, foil, and strip 201 stainless steel, the most common surface finish used is #1 descaling or hot rolled annealing.
- #2D finish is also used with dull finish
- #2B has a smooth finish
- #BA or Bright Annealed finish
- #CBA or Course Bright Annealed surface treatment
- #2BA that offers very glossy finish
- Polished finish offers grit surface
Features of a 201 Stainless Steel
- Durable
- Heat resistance
- Aesthetic
- More hardness
- Good shape
- Alkali-resistance
- No pinhole
- No bubbles
Melting Temperature
Stainless steels are naturally heat-resistant. As for the 201 grades, its melting temperature ranges from 1400 up to 1450⁰C.
Electrical Conductivity
If you are wondering whether 201 stainless steel is electrically conductive, the answer is yes, however, very low. Its conductivity is not really significant compared to copper, iron, gold, etc. Hence, stainless steel 201 grade is not a material that is recommended for applications that require high electric conductivity.
Hygienic and Non-Toxic
201 stainless steel is a very safe material and can be used for industries that deals with food. It is also environmentally-friendly. These materials do not contain any toxic and harmful elements.
Specifications
There are 4 categories of 201 stainless steel specifications including:
Cost. This type of stainless steel is very inexpensive and affordable. Therefore, it is the most common stainless steel used by architects, engineers, designers, etc.
Toughness. The stainless steel 201 has a very strong resistance to impact especially in cold conditions. It provides up to 30% yield strength while also offering excellent ductility. Thus, it is widely used for applications that requires very hard metals.
Resistance. This material is also known because of its high resistance to corrosion. However, its corrosion resistance advantage may become less when used for application where chemicals are present.
Formability. Manufactures should overbend this material when forming to prevent returning to its original shape.
Difference Between 201 and 304 Stainless Steel
In terms of their chemical composition, the 201 contains 5% nickel and 15% chromium while 304 contains 9% nickel and 18% chromium. 201 has low chromium and nickel content, therefore, it has lesser rust resistance than 304. The 304 stainless steel is also brighter in color than 304. In terms of price, 201 is less expensive than 304.
Applications
- Doors
- Windows
- Hose clamps
- Trailers
- Railway cars
- Highway guardrail
- General and highway signage
- Kitchen appliances
- Eating utensils such as spoons, forks, trays, etc.
- Curtain walls
- Furniture
- Decoration
- Medical tools
- Roofing
- Watch cases
- Watchband, and more
