Friction Welding of Sintered Steel and Carbon Steel

Abstract

The friction weldability of sintered high carbon-high chromium steel (PM) and S25C steel was investigated. The welded joint of the as-received PM and S25C steel, the quench-tempered joint after welding and the welded joint of the quench-tempered PM and the as-received S25C steel were made. They were labelled A, B and C joints. A continuous drive type friction welding machine was used. Welding was carried out in the range of the following conditions.Rotational speed: 2440 rpm, Friction pressure: 6.0, 8.0 Kgf/mm2, Upsetting pressure: 10.0, 14.0 Kgf/mm2, Friction time: 3.0, 5.0 s, Upsetting time: 10.0 s.Results of this study are summarized as follows:(1) The A joint are broken in the PM base metal or at the weld in tensile test. As the tensile strength of the as-received PM base metal itself is low, the joint is unsuited for practical use.(2) The C joints are broken at the weld interface or in the heat-affected zone of PM base metal in tensile test. The joint imperfection at the weld interface and the imperfection of joint between powder particles are the causes of fracture in each case.(3) The B joints are broken in the base metal in tensile test and have sufficient strength.(4) The B joint is superior to the quench-tempered PM base metal in bending ductility, impact value and fatigue limit.