HIGH STRENGTH NONMAGNETIC AUSTENITIC STAINLESS STEEL

PROBLEM TO BE SOLVED: To provide a production method where steel wire, bar steel or thin band steel capable of having 0.2% proof stress on high standards whose arrival is considered to be impossible, in the case the expensive alloy elements as the chemical components of austenitic stainless steel are not increasingly added, and in which the securance of nonmagnetism is made possible can be produced with reduced energy and also with reduced equipment load.SOLUTION: Provided is a production method in which a high strength nonmagnetic austenitic stainless steel wire, bar steel or thin band steel in which 0.2% proof stress at room temperature is 0.80 GPa or higher, permeability is below 1.02, and the grain boundary density at an orientation difference angle of 5 degrees or higher in grain boundary density is 2 μm/μmor higher is produced by using commercially available ordinary nonmagnetic austenitic stainless steel, subjecting the same to plastic working such as rolling at a working ratio of 70% or higher in the temperature range of 350 or higher and 650°C or lower. 【課題】オーステナイト系ステンレス鋼の化学成分であり高価な合金元素を増量添加しない場合には、全く到達不可能とされている高水準の０．２％耐力を有し、非磁性を確保することが可能となった鋼線、棒鋼又は薄帯鋼を、省エネルギーかつ設備負荷を軽減して製造を可能とする製造方法の提供。【解決手段】オーステナイト系ステンレス鋼であって、室温における０．２％耐力が０．８０ＧＰａ以上であって、透磁率が１．０２未満であり、更には粒界密度において５度以上の方位差角の粒界密度が、２μｍ／μｍ２以上を有する高強度非磁性オーステナイト系ステンレス鋼線、棒鋼又は薄帯鋼を、市販されている通常の非磁性オーステナイト系ステンレス鋼を素材として、３５０℃以上６５０℃以下の温度範囲において加工率が７０％以上の圧延加工等の塑性加工を施すことにより製造する方法。【選択図】図５