【摘要】 研究了喷射成形超高碳钢的超塑性及其变形前后的显微组织。变形前,喷射态超高碳钢的组织为典型珠光体组织,而变形后,珠光体中的条状碳化物逐渐发生碎化和球化,并弥散分布于晶界处,此外,在铁素体基体中以及碳化物颗粒周围出现了高密度位错亚结构,而基体铁素体晶粒也有所伸长。喷射成形超高碳钢超塑性微观机制是以晶界滑动为主,晶内变形以及位错蠕变起了协调作用。更多还原

【Abstract】 The superplastic behavior of a spray-formed ultrahigh carbon steel (UHCS-3Si) and its microstructure after superplastic deformation were investigated. The typical microstructure of as-sprayed UHCS-3Si was fine lamellar pearlite. The lamellar peralite changed to equiaxed grains stabilized by spheroidized cementite particles distributing at grain boundary during the superplastic deformation. High density dislocation and grain deformation were observed in UHCS after superplastic deformation. The mechanism of superplastic flow is grain boundary sliding (GBS) cooperating with the dislocation creep.更多还原