HUANG Fu-xiang
,
WANG Xin-hua
,
WANG Wan-jun
钢铁研究学报(英文版)
The microstructures of austenitic stainless steel strip were studied using color metallographic method and electron probe micro analysis (EPMA). In the cast strips, there are three kinds of solidification structures: fine cellular dendrite in the surface layer, equiaxed grains in the center and fine dendrite between them. The solidification mode in the surface layer is the primary austenite AF mode because of extremely high cooling rate, with the retained ferrite located around the primary cellular austenite. In the fine dendrite zone, the solidification mode of molten stainless steel changes to FA mode and the residual ferrite with fish-bone morphology is located at the core of the dendrite. The retained ferrite of equiaxed grains in the center is located in the center of broken primary ferrite dendrite with vermicular morphology.
关键词:
strip casting
,
solidification microstructure
,
austenitic stainless steel
,
retained ferrite
ZHOU Guo-ping
,
LIU Zhen-yu
,
YU Shi-chuan
,
CHEN Jun
,
QIU Yi-qing
,
WANG Guo-dong
钢铁研究学报(英文版)
The formation of phosphorous surface inverse segregation (SIS) in twin-roll cast strips of low-carbon steels was studied. High phosphorous strips were fabricated by using a pilot twin-roll strip caster and a melt/substrate contacting apparatus, respectively. Solidification structures of strips were observed and analyzed, and phosphorus distributions along longitudinal sections of strips were investigated and discussed. The results showed that solidification structures of all strips were columnar grains, either integrated or coarse in the strip made by the melt/substrate contacting apparatus or damaged in some degree in cast strips; and that during cast strip solidification, enrichment of phosphorus occurred between columnar grains, and the average phosphorus concentration near the surface in the strip with 015% of phosphorus was measured to be about 027% which was obviously higher than that in the bulk.
关键词:
strip casting
,
phosphorus enrichment
,
inverse segregation
,
steel
,
solidification
