Kobe Steel, Ltd.;SHINKO METAL PRODUCTS CO., LTD.;NHK SPRING CO., LTD.
发明人:
Hatano Hitoshi,Toyotake Kotaro
申请号：
US201013320619
公开号：
US9689051(B2)
申请日:
2010.05.14
申请国别(地区):
美国
年份:
2017
代理人:
Oblon, McClelland, Maier & Neustadt, L.L.P.
摘要：
A hollow seamless pipe for a high-strength spring with reduced occurrence of decarburization in the inner and outer peripheral surfaces, hardened surface layers in the inner and outer peripheral surfaces during quenching, and sufficient fatigue strength is provided. The hollow seamless pipe contains a steel material, which includes 0.2 to 0.7 mass % of C, 0.5 to 3 mass % of Si, 0.1 to 2 mass % of Mn, more than 0 and 0.1 mass % or less of Al, more than 0 and 0.02 mass % or less of P, more than 0 and 0.02 mass % or less of S, and more than 0 and 0.02 mass % or less of N. The C content in the inner and outer peripheral surfaces is 0.10 mass % or more. A thickness of a whole decarburized layer in each of the inner peripheral surface and the outer peripheral surface is 200 μm or less.
