Effects of Heat Input on Upset Welding Characteristics of Spheroidal Graphite Cast Iron to Stainless Steel

Abstract

  Upset welding of spheroidal graphite cast iron to three kinds of stainless steel (SUS430, SUS304, SUS310) was carried out under various welding conditions. The specimen was 10mm in diameter and 100mm in length. Microstructure observation was employed in order to clarify the characteristics of the bonding interface. Vickers hardness, tensile strength, and elongation of the welded specimen were investigated. FCD previously occurred to the melt of the base metal on the bonding interface than SUS. In the upset welding, the melted part on the welded specimen was exhausted to the edge side, and the part changed into a mottle structure. The microstructure of the welded specimen changed into a spheroidal graphite cast iron structure in pearlite matrix from the mottled structure with increasing heat input. Carbidi precipitation of about 10 to 25μm in size was observed on the SUS side bonding interface.