Influence of strength and cold forming on liquid metal embrittlement due to hot-dipping of high strength structural steels

Abstract

Two structural steels were cold deformed and tested via tensile tests to investigate the dependence of cold deformation on liquid metal embrittlement during hot-dipping. It was found that the reduction in area of tensile specimens with a low degree of deformation showed, when tested in liquid zinc, the highest degradation compared with a tensile test in air that had been heated to 450 °C. An increasing degree of deformation leads to a decreasing tendency to form brittle cracks. The material conditions of steel S355J2 with the highest degree of deformation manifested nearly no influence on liquid metal embrittlement. For steel S460N, the amenability to a reduction in area of the highly deformed material was degraded when compared to tests in hot air. The reason for these differences in the extent of liquid metal embrittlement during hot-dipping might have to do with a difference in microstructure, in particular with respect to the grain size and the deformation of the microstructure.