Abstract
Based on the fact that the notch toughness of steel has been improved by accelerated cooling (A.C.) after the finishing rolling, the weldability of notch ductile semi-killed steel A.C.-treated was investigated.
From the results of standard V-notched Charpy, Tipper, Van der Veen and Kahn tests, aging test (by standard V-notched Charpy test), under-bead-cracking test by C.T.S. type, I.LW. maximum hardness test and Commerel test, it was recognized that the weldability of A.C. semi-killed steel is superior to th at of ordinarily rolled semi-killed steel.
