Stainless steel with excellent cold forging properties, hydrogen embrittlement resistance, corrosion resistance, and non-magnetic properties

Abstract

Provided is a stainless steel containing, in % by mass, 8.00 to 30.00% of Ni, 9.0 to 21.0% of Cr, 0.01 to 3.00% of Mo, 0.01 to 5.00% of Cu, and 0.0010 to 0.10% of N. Furthermore, the first invention contains at least one component selected from Al in an amount of 0.001 to 2.0% and B in an amount of 0.0001 to 0.05%, has a micro-strain in a region laying between a steel material surface layer to a depth of D / 4 of 0.0040 or less, and has excellent cold forgeability and hydrogen embrittlement resistance properties. The second invention contains 0.0001 to 0.05% of B and 0.0001 to 0.50% of S and also contains at least one component selected from Al in an amount of 0.001 to 2.0% and Ca in an amount of 0.0001 to 0.05%, has a precipitated B amount of 0.0001% or more in terms of a boride, has an aspect ratio of a sulfide of 50 or less, and has excellent cold forgeability, cutting performance and hydrogen embrittlement resistance properties. The third invention contains 0.0001 to 0.05% of B, has a B grain boundary occupancy of 1% or more, has excellent corrosion resistance and cold forgeability, and is non-magnetic.

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