低碳低合金三相钢的研究与应用

STUDY AND APPLICATION OF A LOW CARBON-LOW ALLOY TRIPHASE STEEL

自行设计一种以Ｓｉ、Ｍｎ为主要合金元素的低碳低合金三相钢，经７００～７４０℃临界区热处理获得（８～１５）％Ａ＋（２０～３０）％Ｍ＋Ｆ不同体积百分比的三相组织。应用光学显微镜、透射电镜、Ｘ射线衍射仪、拉伸试验机研究了三相钢在冷变形过程中的显微组织变化，探讨了冷成型高强度螺栓的强化机制。制成了８．８级、９．８级、１０．９级高强度螺栓。

A low carbon-low alloy steel contahing primarily Si and Mn elements was designed anda triphase microstructure with(8～15)%A+(20～30)%M+F was obtained by intercriticalheat treatment at 700～740℃. The microstructural change during cold deformation was in-vestigated by optical microscope, transmission electron microscope(TEM), X-ray diffrac-tometer and tensile testing machine and the strengthening mechanism of high strength boltsafter cold forming was studied. The grade 8.8, 9.8 and 10.9 high strength bolts had beenmade of the triphase steel.