Effect of Boron on Copper Induced Surface Hot Shortness of 0.1% Carbon Steel

Abstract

Copper in steel is enriched at the steel/scale interface by the selective oxidation of iron and causes liquid embrittlement at the steel surface during hot working. The development of method for the suppression of the hot shortness is desired for the promotion of recycling of steels. Effect of boron on the hot shortness was investigated from the viewpoints of oxidation rate, grain size, micro-structures of Cu-enriched phase and penetration of the liquid Cu-enriched phase. Addition of a low content of boron is effective on the suppression of the hot shortness. This suppression is attributed to the effect of boron to restrict the penetration of liquid Cu-enriched phase into austenite grain boundaries.