Microstructure and hot ductility in austenitic stainless steel slab shell
The microstructures in austenitic stainless steel slab (ASS) shell have a direct effect on its hot ductility. Making use of special-designed equipment，elevated temperature tests were carried out on THERMORESTOR-W thermo-simulation machine. Small tensile specimens were cut from austenitic stainless steel Cr15Mn9Cu2Ni1N slab core and shell with various distances from slab surface. Results show that, when deformation temperature was higher than 1050 ℃, RA of specimens cut from shell surface was lower, and those increased gradually from surface to inside, and RA of specimen at the distance of 27 mm from the shell surface was the highest. RA of specimens in slab core was lower than that in slab shell except surface. When deformation temperature was lower than 1050 ℃, RA of specimen did not varied apparently in whole shell. According to microstructures of the slab, it was found the cooling rate of shell surface was so high during solidification that δ-ferrite did not solidify as primary phase entirely in liquid phase and then transform austenite, instead, austenite solidified directly in retained liquid phase between dendrites. This change of solidification mode was most severe in the shell surface, which decreased its hot ductility. Owing to coarse equiaxed structures in core, the hot ductility was lower than that in shell.
HOU Guo-qing ZHU Liang MA Rong WEI Peng
State Key Laboratory of Gansu Advanced Non-Ferrous Metal Materials, Lanzhou University of Technology, Lanzhou 730050, China
国际会议
桂林
英文
1-6
2010-11-16（万方平台首次上网日期，不代表论文的发表时间）