301 is a low nickel, higher carbon variant of 304. Its dominant purpose is to increase the work hardening capability of this austenitic grade of stainless steel to produce very high strength thin strip and wire.
Approximate Composition – 16.5% Cr, 7% Ni, 0.07% C (Exact composition ranges vary between EN and ASTM standards).
This grade combines the following characteristics:
- Good pitting corrosion resistance but slightly lower than 304 due to lower Cr
- Very high work hardening rate leading to very high strength. Minimum UTS of 1900 MPa possible compared to 1300 MPa for 304 (1.4301) in the EN standards for springs
- Work hardening producing high level of magnetic response
- Higher carbon leading to greater susceptibility to intergranular corrosion
The high work hardening rate of 301 allows it to be used for a wide range of applications where “springiness” is the primary requirement. The degree of “springiness” varies with the amount of cold rolling for strip or cold drawing for wire products. In the EN spring steel standards, the cold worked conditions are designated in the form +C700 up to +C1900 where the number stands for the minimum UTS in MPa. The ASTM system uses designations such as ¼ hard, ½ hard, ¾ hard and full hard, which cover the range of minimum UTS from 860 to 1275 MPa for grade 301.
Applications which illustrate these features include:
Springs, banding, clamps, clips, airframe sections, roll formed sections, wire mesh, seat belts, push feed systems, sash windows.