| 摘要 |
PROBLEM TO BE SOLVED: To provide a nonmagnetic steel which combines high strength and low magnetic permeability, and is excellent also in workability.SOLUTION: The high-proof stress nonmagnetic steel includes, by mass, C: 0.8-1.2%, Si: 0.25-2.0%, Mn: 5.0-12%, N: 0.01-0.10%, P: at most 0.03% (excluding 0%), S: at most 0.03% (excluding 0%), Cu: at most 0.1% (excluding 0%), Ni: at most 0.1% (excluding 0%), and a remainder of iron and inevitable impurities, wherein at least 99 area% of a microstructure is an austenite structure, an austenite grain size is at least 5.0, a P value expressed with the following formula (1) is at least 215, and a relative permeability is at most 1.10. P value =158[C]+64[Si]+0.45[Mn]+46 [Cr]+548[N] ... (1), wherein in the formula (1), [] implies a content (mass%) of each element. |
