MICROSTRUCTURES AND ELEMENTS DISTRIBUTION IN THE TRANSITION ZONE OF CARBON STEEL AND STAINLESS STEEL WELDS

Abstract

The change of microstructures and elements distribution around the carbon fusion line in carbon steel and stainless steel welds were investigated by means of optical microcopy (OM), scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The chemical composition profiles of the interface lay varied continuously from the base metal to the weld zone of 80µm width. This study showed that the microstructures and properties of this zone depended on local composition and cooling rate. Fully Martensitic layer with 5µm of width was observed along the fusion line. Then, a fully Austenitic zone spreads over 20µm and a two-phase γ + δ microstructure typical of a stainless steel was documented from the fusion line to the weld metal. The hardness value of Martensitic is the highest and recording 243 HV. The results may be used to overcome the limitations of the weld structure zone between carbon steel and stainless steel for application in the shipbuilding industry.

Keywords

• Carbon steel
• stainless steel
• dissimilar metal welds
• element distribution