STUDY THE MICROSTRUCTURE AND IMPACT TOUGHNESS OF WELDED JOINTS FOR WELDOX 700MC HIGH STRENGTH STEEL

The use of high-strength steels (HSS) provides several potential advantages. However, the progress in a steel technology continually demands a new developments in welding processes to produce a weld metals with a mechanical properties equivalent to the base metal. To achieve this, however, a better understanding of chemistry- and microstructure-property relationships in a high strength steel weld metal is needed. In the present work, the Weldox700MC high strength steel was welded by the mixed gas arc welding process. The microstructure and chemical composition as well as the impact toughness of the weld line, fusion area and heataffected zone metal were analyzed, which provide a theoretical guidance to the physical properties of the welding different parts. The results show that weldox700MC low alloy high strength steel is a kind of good welding steel with the uniform microstructure distribution of a circular ferrite in a different welded regions which can be increase the impact toughness.