The relationship between microstructure morphology and mechanical properties of the low-carbon steel(Fe-0.20 C-2.59 Mn-2.13 Si)treated by diff erent intercritical annealed quenching and partitioning(Q&P)processes ...The relationship between microstructure morphology and mechanical properties of the low-carbon steel(Fe-0.20 C-2.59 Mn-2.13 Si)treated by diff erent intercritical annealed quenching and partitioning(Q&P)processes was investigated through interrupted tensile tests plus quasi-situ electron backscatter diff raction measurements.Results show that size and distribution of retained austenite(RA)directly aff ect the sequence of deformation induced martensitic transformation.As strain increases,the equiaxed RA grains wrapped by ferrite transform fi rst,followed by the equiaxed and fi lm-like RA grains adjacent to martensite.Compared with traditional intercritical annealed Q&P steel with equiaxed structure,the steel with quenching pretreatment contains uniform lamellar structure and the relatively fi lm-like type of RA,leading to the higher yield strength,tensile strength,and elongation,as well as the steady increase in dislocation density upon straining.展开更多
基金supported by the National Key Research and Development Program of Thirteenth Five-year Plan Period(No.2017YFB0304400)the National Natural Science Foundation of China(No.51574028)。
文摘The relationship between microstructure morphology and mechanical properties of the low-carbon steel(Fe-0.20 C-2.59 Mn-2.13 Si)treated by diff erent intercritical annealed quenching and partitioning(Q&P)processes was investigated through interrupted tensile tests plus quasi-situ electron backscatter diff raction measurements.Results show that size and distribution of retained austenite(RA)directly aff ect the sequence of deformation induced martensitic transformation.As strain increases,the equiaxed RA grains wrapped by ferrite transform fi rst,followed by the equiaxed and fi lm-like RA grains adjacent to martensite.Compared with traditional intercritical annealed Q&P steel with equiaxed structure,the steel with quenching pretreatment contains uniform lamellar structure and the relatively fi lm-like type of RA,leading to the higher yield strength,tensile strength,and elongation,as well as the steady increase in dislocation density upon straining.
