【摘要】 研究了固溶态0Cr13铁素体不锈钢在室温1-4道次等径转角挤压(ECAP)过程中的结构演化和力学性能.结果表明:0Cr13钢在挤压变形过程中晶粒的细化行为在介观上表现为在形变带作用下的晶粒分割;微观上则表现为位错分割机制下的晶粒碎化。四道次后形成了均匀的等轴超细晶结构,平均晶粒尺寸约349 nm。室温拉伸和冲击测试结果表明,实验钢在一道次EACP加工后强度提高,韧塑性下降。后续更高道次挤压变形在使样品强度继续提高的同时,冲击韧性也适当改善了。高道次(3、4道次)样品的冲击韧性大致可以恢复到挤压加工前的～30%。因晶粒细化和动态回复而导致的静力韧度提高和断裂机制转变,是造成高道次样品冲击韧性改善的原因。更多还原

【Abstract】 Microstructural evolution and mechanical properties of a solution-treated 0Crl3 ferritic stainless during the process of equal-channel angular pressing(ECAP) for 1-4 passes at room temperature were investigated.The results showed that the microstructural refinement of 0Crl3 steel during ECAP process presented as the grain subdivision by the induced deformation bands in mesoscale,and the crystal disintegration through dislocation segmentation model in microscale.As a result,a homogeneous ultrafinegrained structure developed in the 4-pass ECAP sample,and the corresponding average grain size is about 349 nm.Tensile and impact tests at room temperature showed that the strength of the tested steel increased and its ductility decreased after ECAP deformation for a single pass.However,further pressings (2nd,3rd and 4th) resulted in a certain degree of improvement in impact toughness with enhancing strength simultaneously.The impact toughness of the multi-pass(3 and 4 passes) samples approximately returned to about 30%of the pre-pressing level.The enhanced static toughness and the changes in fracture mechanism resulted from grain refinement and dynamic recovery are responsible for the improved impact toughness of the multi-pass ECAP samples.更多还原