In previous paper, it was presumed that the most important factor to cause the grain-boundary liquation in the heat-affected zone of test high strength steel (HY-type, HT100) was the low-melting point eutectic reaction between Cr and Ni elements which had been swept up and enriched to grain boundary. In this paper, the further investigation on the grain-boundary liquation was conducted, especially to obtain a certain understanding of the effects of sulfides on it, using a free cutting steel. As

more »

... a result of this study, it became to be decisive that the sulfides, such as MnS, were secondary and not important factor of the grain-boundary liquation in HAZ of HY-type high strength steel (HT100), and that the primary factor of it was the most likely to be the eutectic reaction between Cr and Ni swept up and enriched to grain boundary.