The difference between 201 and 202 stainless steel is relatively subtle compared to the differences between the 200 series and the 300 series (like 304 or 316). Both 201 and 202 are part of the 200 series of austenitic stainless steels, characterized by substituting manganese and nitrogen for a portion of the nickel content found in the 300 series, making them lower-cost options.
Key differences often lie in slight variations within their specified chemical composition ranges:
- Chromium Content: Type 202 generally has a slightly higher chromium range (typically 17-19%) compared to Type 201 (typically 16-18%). This might give 202 a marginal edge in general corrosion resistance, though both are significantly less resistant than 304.
- Nickel Content: Type 202 usually has a slightly higher nickel range (typically 4-6%) compared to Type 201 (typically 3.5-5.5%).
- Manganese Content: Both utilize high levels of manganese, but the ranges might differ slightly, often with Type 202 having a range like 7.5-10% while 201 might be around 5.5-7.5%.
- Nitrogen Content: Both grades contain nitrogen (up to 0.25%) to help stabilize the austenitic structure and increase strength.
Performance and Properties: Due to these compositional similarities, the mechanical properties (strength, ductility, formability) and general corrosion resistance of 201 and 202 stainless steels are very close. Both offer higher strength than 304 in the annealed condition but lower corrosion resistance. The slightly higher chromium in 202 might offer a very minor improvement in corrosion resistance, but for practical purposes in most applications where these grades are suitable (mild environments), the difference is often negligible.
Applications: Their application areas largely overlap. Both are used for cost-effective solutions in applications like kitchenware, utensils, restaurant equipment, architectural trim (indoor), hose clamps, and structural parts where high corrosion resistance is not the primary driver. The choice between Grade 201 and Grade 202 might sometimes come down to regional availability, minor cost differences at a particular time, or specific manufacturer preferences rather than significant performance distinctions.
In summary, 201 and 202 are very similar low-nickel, high-manganese austenitic stainless steels. While there are minor differences in their specified compositional ranges, their overall performance characteristics and suitable applications are largely interchangeable, both serving as economical alternatives to 304 stainless steel in less demanding environments.