This report deals with pre- and post-heat treatment in friction welding of SCM3 steel to S45C steel. Main results obtained in this study are as follows:
(1) There is little difference in hardness and structure between the welded joint of pre-weld heat treated base metals and that of as-received base metals.
(2) In tensile test, every welded joint fractured in S45C steel base metal irrespective of the procedure of heat treatment.
(3) Tough welded joint of SCM3 steel-S45C steel is obtained by post-weld heat treatment of 850°C oilquenching-600°C tempering. The joint thus obtained has adequate tensile strength, sufficient ductility and high impact value.