https://www.jstmetal.com/2023/06/anh-huong-cua-nhiet-do-austenit-hoa-den-qua-trinh-tiet-pha-cacbit-thu-cap-cua-gang-trang-27-crom/

Abstract

A 27 wt. % Cr white cast iron has been subjected to various austenitization heat treatments. The transformation of the matrix phase as well as the precipitation of secondary carbides at the austenitization temperature have been clearly determined in this paper. The results showed that secondary carbides precipitated along the defect sites of the austenitic phase at 900 oC during the austenitization. They grew up within austenit matrix, and there exist some retained austenit. The amount and size of secondary carbides increase as the austenitization temperature rises to 1000 oC. At 1050 oC/3 h, the size of secondary carbides reduces significantly with a high distribution density in the matrix phase. Higher austenitization temperatures cause the matrix to become more stable and make it more difficult to produce secondary carbides, as well as increase the number of defects in the matrix. The microhardness of the austenit matrix is affected a lot by how many and how big the secondary carbide particles are. At 1050 oC/3 h, the micro-hardness is the highest one. When the temperature of austenitization goes above 1050 oC, the micro-hardness of the matrix reduces.