【摘要】 本文研究了预形变亚温淬火双相15钢的显微组织,力学性能特点和断裂行为。试验结果表明,采用适当的室温预形变与短时加热亚温淬火相结合的工艺,可使15钢获得马氏体与铁素体相间定向分布的复合组织,是发展高强度(σ_b≈100kg/mm~2,δ≈10%)铁素体——马氏体双相钢的有效方法之一。拉伸断口形貌随原始组织及预形变量的大小而有所不同。虽然在短时加热亚温淬火双相钢中铁素体和马氏体均可对钢的强度作出贡献,但实际参与形变和断裂过程的马氏体数量远小于定量金相分析所得结果,在利用混合律估算强度时应予以注意。更多还原

【Abstract】 Microstructures, mechanical properties and fracture behavior of a plain carbon (0.17%C) dual-phase steel intercritically quenched after cold deformation were studied. Experiments show when appropriate prior cold deformation combined with short time heating are used before quenching, a directionally distributed dual-phase microstructure can be obtained. This technology may be one of the useful methods for developing ferrite-martensitic dual-phase steels with high strength and appreciable ductility(σ_b≈100kg/mm~2, δ≈10%). The specific character of tensile fracture depends on the initial microstructure and the degree of cold deformation prior to qucnching. Although both ferrite and martensite grains contribute themselves to the strength of the steel, the real volume fraction of martensite joining in fracture processes is much less than that obtained by quantitative analysis. This condition must be noticed when the law of mixtures is to be used to estimate the strength of dual-phase steels.更多还原