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
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
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 Centigrade.
Weldability
Reasonable, although sensitive to intergranular corrosion in the heat affected zone where thickness exceeds 6mm.
Post-weld cleaning and passivation is crucial.