PLUG FOR ROLLING SEAMLESS STEEL PIPE, METHOD FOR MANUFACTURING SAID PLUG, AND METHOD FOR MANUFACTURING SEAMLESS STEEL PIPE IN WHICH SAID PLUG IS USED

摘要

Provided is a technique for significantly increasing the life of a plug used under severe conditions such as rolling of a seamless high-alloy steel pipe. Specifically, a plug for rolling of a seamless steel pipe, the plug having an oxide layer composed of a cobalt-base oxide on a surface of a coating layer formed by coating a surface of a base metal with cobalt or a cobalt-base alloy, a method for manufacturing the plug and a method for manufacturing a seamless steel pipe using the plug.