Abstract
Stabilized type stainless steel is processed to get finer grain size even at higher solutioning temperature. The detailed process is as follows. Carbides are fully dissolved at high softening temperature, and then, after cold work recrystalization is performed at lower solutioning temperature. Precipitation of fine carbides during the solution is proved to be responsible for the fine grain by preventing grain growth.
SUS 347 HTB tubes (JIS) were made by the above process and examined for creep rupture. They showed higher creep rupture strength compared to the tubes with the lower softening temperature process. Advantage of this new process is to allow higher solutioning temperature which provides higher creep rupture strength.
