共查询到17条相似文献,搜索用时 46 毫秒
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据美国《Metall Trans》A集1989年,第1期报道钢中VC、V(C,N)、AlN第二相粒子对奥氏体晶粒粗化行为的影响不尽一致。 1 引言具有铁素体一珠光体组织的高强度低合金钢和采用控轧控冷工艺的微合金化钢的强韧性同铁素体晶粒尺寸紧密相关。细化铁素体晶粒对强度和韧性两者都有利,而其它的强化方法往往使韧性受损。铁素体晶粒细化的先决条件是原始奥氏体晶粒也小,因为铁 相似文献
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文章总结了用第二相粒子细化晶粒的理论。比较了各种第二相粒子细化晶粒的效果,提出使用SiO2粒子细化HSLA钢晶粒的可能性。理论分析表明,在凝固过程中有可能获得较高的SiO2粒子体积分数。此外,还进行了实验室研究,得到了较小尺寸的SiO2粒子。 相似文献
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Xianchun Dong;Xinyao Liu;Ning Cai;Dawei Zhang;Xiazhou Zhang;Xuetao Li 《钢铁钒钛》2023,44(6):192-197
A 22.5 × 9.0 wheel rim made of Ti and Nb precipitation strengthened 600 MPa wheel steel was manufactured by continuous flash butt welding process to. The lap joint of rim and spoke was welded under gas shielded welding process. The flash butt welded joint of the rim cracked during the flaring process, thinned during rolling forming process and cracked during expansion process. Consequently, the comprehensive scrap rate was 37%. When the wheel was subjected to radial fatigue test for 800000 cycles, fatigue cracking occurred at the weld root of the lap between the rim and the spoke. The fracture, microstructure, hardness and precipitated phase of wheel steel joint were analyzed. The results show that the hardness of butt welded joints presents \"saddle\" local softening characteristics, and the hardness of lap joints presents \"basin\" local softening characteristics. In the CGHAZ the grains coarsen, while the second phase particles below 20 nm dissovle significantly. In the FGHAZ the grains grow, with the second phase particles below 20 nm disappear and particles above 20 nm coarsen, leading to softening behavior of HAZ. 相似文献
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重点讨论了高强度钢筋生产常用的微合金元素及其强韧化机理,介绍了包钢在微合金技术生产热轧带肋钢筋方面取得的成绩与经验。指出未来的钢筋生产主要依靠新技术、新工艺及低成本化技术,同时应大力开发高强抗震钢筋产品以满足建筑结构的高安全性。 相似文献
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钒氮微合金化高强度球扁钢的强韧化机制 总被引:1,自引:0,他引:1
针对球扁钢在孔型轧制时球头、腹板部位组织性能不均匀的问题,研究了钒氮微合金化技术改善高强度球扁钢截面均匀性的作用机制。采用ANSYS有限元模拟了球扁钢轧后冷却温度场的分布。结果表明,球扁钢轧后冷却过程中球头心部冷却较慢,腹板冷却较快。950℃终轧后冷却150S时,球头心部、腹板温度差异约为120℃;对比分析了钒和V—N微合金化球扁钢球头/腹板部位组织、性能的差异。和钒钢相比,V—N球扁钢屈服强度显著提高,球头心部、腹板强度差异约为5~10MPa。V—N设计细化了球扁钢的显微组织,球头心部、腹板平均铁素体晶粒尺寸仅相差1.24μm,低温韧性显著提高。球头心部较慢的冷却速度促进了钒的析出,细化了钒析出物的粒度,显著改善了球扁钢孔型轧制时不同部位冷却速度、变形量差异造成的截面不均匀性。 相似文献