Nippon Steel Corporation

Youji Yamamoto

Motofumi Koyuba

Hiroshi Murayama

A method for the production of an electric seam welded steel pipe for oil-well use which has good resistance to collapse pressure and souring, by providing a steel containing 0.08-0.26% C by weight, 0.8-1.9% Mn by weight, 0.5% or less Si by weight, the remainder being Fe and unavoidable impurities, subjecting the steel to hot rolling, and hardening, and coiling the treated steel at a temperature not exceeding 250.degree. C., after which the steel is then formed into tubular form and welded by electric resistance welding to produce an electric seam welded pipe, and the weld heat affected zones of the pipe are subjected to heating to a temperature of 900.degree. C. or more to effect hardening, and then the whole pipe is tempered.

Growing community of inventors

Tokai, Japan

Youji Yamamoto