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71.
研制出一种微合金化中碳结构钢作为打叶刀基本材料,研制出一种新型的使碳化物颗粒与钢铁基体牢固结合的复合焊接新工艺,由此研制生产出可替代进口的高性能复烤打叶刀,其主要使用性能达到或超过国外进口产品.对打叶刀基体材料的微合金化设计及热处理工艺设计、新型复合焊接工艺的优化及碳化物颗粒尺寸的优化进行了深入的分析探讨. 相似文献
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对0.14C-0.016V-0.014N的低碳微合金V-N钢分别进行终轧温度为950,900,850℃、形变量为30%,40%,50%的控制轧制;对轧后试样进行了拉伸试验、显微组织分析、晶粒度以及铁素体含量测定.结果表明,轧制形变量对试验钢性能和组织有明显影响.降低轧制温度及增大轧制形变量,晶粒度增大,晶粒尺寸减小,钢的强度提高. 相似文献
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76.
The inclusions in titanium containing microalloyed steel with different calcium contents were studied by metallographic microscope, SEM and EDS, to explore the influence of calcium content on the species, size, quantity and morphology of inclusions. The results show that size and quantity of non metallic inclusions in the steel decrease, and the inclusion clustering is alleviated after 0.13% calcium treatment. Part of Ti content in the inclusion of microalloy steel can be reduced, and the recovery rate of Ti is improved after 0.25% calcium treatment, so as to reduce the harm of inclusion and the production cost. 相似文献
77.
Low carbon microalloyed steel containing 0.062% C, 2.34% Mn, 0.044% Nb, 0.029% Ti, 0.032% V in mass fraction and small amount of B was prepared in laboratory. Slabs of the steel were rolled into plates of 6 mm in thickness followed by accelerated cooling. The plates possess very high yield strength and reasonable ductility, and the yield ratio is about 0.8. Ultra-fine ferrite structure with micrometer dimension was observed in the surface layer of the plates. Moreover, the effect of the finishing rolling temperature on the final microstructure and formation mechanism of ultra-fine ferrite as well as the γ-αtransformation behavior of the steel was discussed. 相似文献
78.
设计了低温回火工艺,使50CrV钢的硬度提高,通过对比实验和采用透射电镜,探讨了低温二次硬化产生的机理,结果表明,低温回火时VC的弥散折出导致了50CrV钢的硬度升高,微合金钢中强碳化物形成元素Nb,V,Ti的沉淀强化和固溶强化引起低温二次硬化。 相似文献
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Using Gleeble 1500 system, the influence of holding time on bainite transformation in deformed niobium microalloyed steel during continuous cooling was analyzed, and the carbides in upper bainite were also systematically researched. The results show that the occurrence of the static recrystallization decreases the amount of bainite with an increase in the holding time and the emergence of retained austenite (RA) with the longer holding time. Two types of carbides were observed in upper bainite with regard to their precipitation sites. They either existed between the bainite ferrite laths or co existed with RA. The formation mechanism of two kinds of carbides was analyzed by combining TEM micrographs with the model. 相似文献