Experimental Studies on the Weld Heat-affected Embrittled Zone in Mn-Si High Tensile Strength Steels

Abstract

For mild steels it has been recognized that the V-notch Charpy Impact value or the weld heat affected embrittled zone, 10 to 14mm apart from the center of welded bead, is decreased from the value of base metal. This paper deals mainly the experimental study on the similarly embrittled zone in high tensile Mn-Si steels. Standard V-notch Charpy test was employed to evaluate the notch toughness in the embrittled zone in eight high tensile Mn-Si steels, namely N3, N6, K1, K4, M3, M6, Y4 and Y6.
The main conclusions are as follows:—
1. Al inear relationship was found between the degree of embrittlement and the transition temperature of base metal, the higher the embrittlement, the higher the transition temperature.
2. The degree of. embrittlement and the transition temperatures of the tested high tensile Mn-Si steels were lower than that of ordinary mild steels.
3. The maximum temperature attained in the embrittled zone was lower than the Al transformation point.