What is grade 201 Stainless steel?

Type 201 is an austenitic chromium-nickel-manganese stainless steel that was originally developed to conserve nickel, as nickel prices were increasing. The nickel is replaced by the addition of manganese and nitrogen. Austenitic steels are those which contain between 16 and 26 percent chromium and up to 35 percent nickel.

 

Increased interest in grade 201

200 series stainless steels are not new, but since they have a much lower nickel content than the 300 series, the very high nickel price over recent years has led to significantly more interest. Additionally, there is a continuous programme of development designed to improve existing grades of stainless steel and produce new ones.

 

Properties

Type 201 is a non-magnetic, low-nickel, austenitic stainless steel. It comprises of 16%-18% chrome, 5.5%-7.5% manganese and 3.5%- 5.5% nickel. The manganese it contains provides corrosion resistance and replaces the nickel in a 2:1 ratio. The substantially lower nickel content makes it less expensive than 304, with no loss of resistance to corrosion in most applications.

 

Suitable environments

The greater nitrogen content in type 201 gives a higher yield strength and improved toughness than in type 301 stainless steel, especially at low temperatures. It is non-magnetic in its annealed condition, but it becomes magnetic when cold worked. 201 stainless steel bends and tensions easily. It is overall a very easy metal to work with. It is most appropriate to an environment where it isn't exposed to solvents, chemicals, sewage etc. While it is excellent in normal environments such as those that involve rain, vehicle exhausts and smog, it is not as corrosion resistant as 304 and 316 stainless steels, and therefore is not recommended for structural outdoor applications because of its susceptibility to crevice corrosion and pitting.

 

Treatments

Type 201 stainless steel can be fabricated by bench forming, roll forming and brake bending but is not possible to harden by heat treatment. It can be annealed at 1850 – 1950 °F (1010 – 1066 °C), then water quenched or rapidly air cooled. Rapid cooling through the carbide precipitation range is necessary to keep the carbides in solution and prevent sensitisation. Type 201 can be welded by all the conventional methods applied to 18 percent chromium, 8 percent nickel steels.

 

Applications

Typical uses for grade 201 stainless steel include:

• Kitchen appliances

• Restaurant equipment

• Cooking utensils

• Sinks

• Automotive trim

• Windows and doors

• Railway cars

• Grade 201 v 301