Application of Induction Heating for Production of Heat-treated Low Alloy and Stainless Steel UOE Pipes

High quality large diameter welded pipes have been developed by UOE process followed by induction heat treatment such as quenching and tempering, stress relieving, or solution annealing. This paper describes about the manufacturing process, selections of welding consumables, and mechanical properties of products such as heavy wall and high strength steel pipes, low alloy steel pipes (3.5% Ni and 21/4Cr-1Mo) and Type 304L stainless pipe. The advantages of heat treatment after welding are summarized as follows; 1) Enlargement of manufacturable range for wall thickness and grade of strength (QT), and 2) Improvement of properties of seam welds as well as pipe body (QT, SR, ST).