Solidification structure in a cast B-bearing stainless steel

Solidification microstructure of a cast stainless steel containing 1.5-2.5 wt.%B has been examined by means of the optical microscopy (OM), the scanning electron microscopy (SEM), the electron probe microanalyzer (EPMA), energy dispersive X-ray spectrometry (EDS), X-ray diffraction (XRD) and Vickers microhardness. The as-cast microstructure consists of the M-2(B,C) borocarbide and the austenite. The borocarbide is continuously distributed over the austenite. There are some broken-networks in the local location of borocarbide. Moreover, the distribution of alloy elements is not homogeneous in the cast B-bearing stainless steel. Boron element is mainly distributed over the borocarbide, carbon element is mainly distributed over the matrix. Chromium element is mainly distributed over the borocarbide, and there are also some chromium elements in the matrix. Nickel element is mainly distributed over the matrix and silicon is insoluble in the borocarbide. (C) 2007 Elsevier B.V. All rights reserved.