Postweld heat treatment process of carbon steel and low alloy steel

摘要

The creep strength of a welded joint portion is improved, and damage of the welded joint portion based on the generation or development of cracks is suppressed. A postweld heat treatment process, wherein a welded joint made of carbon steel and low alloy steel is held within austenite single-phase temperature range for a given time and subsequently the joint is cooled by air-cooling or by slow cooling at a cooling rate lower than that of the air-cooling.