Stainless Steel 201, 201L, 202, 204

200 Series stainless steels are not new – In fact they have been around for many years. To date they have traditionally not proved very popular outside the USA. However, since they have a much lower Nickel content than 300 Series Austentics, the very high Nickel price over recent years has led to significantly more interest. Equally, stainless steel producers have an ongoing programme of development designed to enhance existing grades and produce new grades. These new grades are sometimes developed for specific end uses and sometimes to improve upon an existing grade.  


Features:

-> Lower nickel than 300 series – with it being replaced by Manganese

-> Thus lower cost than 300 series

-> Similar mechanical & physical properties to 300 series

-> Similar fabrication performance to 300 series, including deep-drawing

-> Corrosion resistance similar to 430 (i.e. not nearly as good as 300 series)

-> High carbon may cause stress corrosion cracking, especially after welding thicker material

-> Non Magnetic


Performance Comparison:

-> Formability: Similar to 304, better than 430

-> Strength: Stronger than 304 (and 430)

-> Corrosion Resistance @20 C: Similar to 304, better than 430 but susceptible to stress corrosion cracking / intergranular corrosion especially after welding

Chemical Composition

Chemical Element -> % Present

Chromium (Cr) -> 16.00 - 18.00

Manganese (Mn) -> 6.80 - 8.50

Nickel (Ni) -> 2.00 - 5.00

Nitrogen (N) -> 0.0 - 0.25

Iron (Fe) -> Balance

Properties

Physical Property -> Value

Density -> 7.80 g/cm³

Thermal Expansion -> 17 x10^-6 /K

Modulus of Elasticity -> 200 GPa

Thermal Conductivity -> 15 W/m.K

Mechanical Property -> Value

Proof Stress -> 310 Min MPa

Tensile Strength -> 655 Min MPa

Elongation A50 mm -> 40 min %

Alloy Designations

AISI 201 stainless steel corresponds to the following specifications:

-> UNS20100 / EN1.4372 / JIS SUS 201

AISI 201L stainless steel corresponds to the following specifications:

-> UNS20103 / EN1.4371

AISI 202 stainless steel corresponds to the following specifications:

-> UNS20200 / EN1.4373

AISI 204C stainless steel corresponds to the following specifications:

-> UNS20400 / EN1.4597

Supplied Forms

-> Sheet

-> Plate

Applications

200 series austenitics are typically used to replace types 304 and 301 as well as Carbon (Chrome-Manganese) Steels mainly for indoor use for low corrosion applications at room temperature

-> Furniture

-> Bins

-> Cookware & Serving Bowls

-> Window Channel Spacers

-> Safety Shoes (mid-sole protector)

-> Deep drawn kitchen equipment – e.g. Cookware & Sinks

-> Hose Clamps

-> Trailer Frames

-> Industrial Strapping

-> Railway Rolling Stock

There is also grade 201LN for welded constructions, structural uses and low temperature applications  - Examples include sides & roofs of trains, liquified gas storage vessels, structural members/chassis of railway rolling stock, trucks & trailers, coal handling equipment

Performance Comparison

The 200 series grades perform at a similar level to grades 304 and 301 in low corrosion, mainly indoor applcations at room temperature.

Corrosion Resistance

The 200 series grades perform at a similar level to grades 304 and 301 in low corrosion, mainly indoor applcations at room temperature.

Not recommended for use in Chloride environments.

Heat Resistance

Oxidation resistance is similar to grade 1.4310 (301) up to 840 ºC.

Weldability

Reasonable, although sensitive to intergranular corrosion in the heat affected zone where thickness exceeds 6mm.

Post-weld cleaning and passivation is crucial.

source: https://www.aalco.co.uk