发明名称 STEEL WIRE FOR BOLT EXCELLENT IN COLD HEADABILITY AND DELAYED FRACTURE RESISTANCE AFTER QUENCHING AND TEMPERING, AND BOLT
摘要 PROBLEM TO BE SOLVED: To provide a steel wire for bolt excellent in cold headability and delayed fracture resistance after quenching and tempering.SOLUTION: A steel wire for bolt includes, by mass, 0.3-0.6% C, 1.0-3.0% Si, 0.10-1.5% Mn, over 0% to 0.020% or less P, over 0% to 0.020% or less S, 0.3-1.5% Cr, 0.02-0.10% Al, 0.001-0.02% N, and the balance iron with inevitable impurities. The ferrite grain size number is No. 6-12 at a position of steel wire diameter d×1/4, a proportion of carbide with an aspect ratio of 2.0 or less in an entire carbide is 70% or more, and a C content at a position 0.1 mm deep from a surface is 60-120% C content of a base material. The steel wire for bolt is excellent in cold headability and delayed fracture resistance after quenching and tempering.SELECTED DRAWING: None
申请公布号 JP2016186098(A) 申请公布日期 2016.10.27
申请号 JP20150066204 申请日期 2015.03.27
申请人 KOBE STEEL LTD 发明人 MATSUMOTO YOSUKE;CHIBA MASAMICHI
分类号 C22C38/00;C22C38/34;C22C38/50;F16B35/00 主分类号 C22C38/00
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