Distribution of arsenic on micro-interfaces in a kind of Cr, Nb and Ti microalloyed low carbon steel produced by a compact strip production process

Highlights: → We evaluate the effect of Ti, V and Nb on grain boundary segregation of arsenic in steel. → Arsenic segregates strongly on grain boundary at the base-metal/scale interface. → Arsenic segregates on subgrain boundaries in the hot rolled steel strip. - Abstract: Distribution of arsenic on micro-interfaces in the Cr, Nb and Ti microalloyed low carbon steel strip was investigated by SEM, TEM and EDS in a compact strip production (CSP) and a following reheating processes. It is discovered that, in the CSP processes, the arsenic content within grains at the half thickness of the strip was a little higher than that at the grain boundaries, which was attributed to a quicker occupying of vacancies by carbon, Nb and Ti atoms on grain boundaries. However, arsenic segregated strongly on grain boundaries at the interface between the base metal and the oxide scale, where it had a maximum arsenic content of 2.93 wt.%. The strongly segregation of arsenic on grain boundaries at the interface between the base metal and the oxide scale may lead to difficulties in the subsequent production galvanized sheet with the hot rolled CSP strip that contains arsenic. When the hot rolled strip (CSP) was reheated to 1100 deg. C, held for half an hour, arsenic segregated strongly on subgrain boundaries for the availability of more vacancies caused by the solid solution of alloy carbonitrides.