【作者】 徐光；

【导师】 徐楚韶；

【作者基本信息】 重庆大学 ， 钢铁冶金， 2006， 博士

【摘要】 金属铁素体低温变形技术是一种新的生产工艺,适用于低碳钢和超低碳钢的加工。国外有关超低碳钢铁素体低温变形方面的研究起步较早,研究的范围也比较广泛,涉及的内容较多,研究内容包括变形工艺制度对加工产品组织和性能的影响、变形工艺制度对热加工过程中静态、动态再结晶的影响、变形工艺制度对产品深冲性能的影响、微合金元素对变形金属组织和性能的影响等。与此相应的是国外已经将这种金属加工新技术成功地应用于超薄规格、深冲带钢的生产中。但是国内有关超低碳钢铁素体变形方面的研究起步较晚,研究内容非常少、研究深度不足,目前已经发表的10余篇研究论文大部分是关于超低碳钢铁素体变形时的织构方面的,关于超低碳钢铁素体变形时的一些基本的热变形行为方面的报道很少,比如超低碳钢铁素体变形时的流动应力模型还没有报道;超低碳钢铁素体变形过程中的动态再结晶、静态再结晶报道的也极少。与此相对应的是国内目前还没有将这一具有一系列优点的新的金属加工工艺应用到超薄深冲带钢的生产中。低温变形时金属的物理冶金学行为与高温奥氏体变形有较大的不同,变形之前和变形过程中,被加工金属会发生奥氏体→铁素体相变,这种相变对变形过程中和变形后的金属冶金行为都有重要的影响,铁素体的相变和再结晶是低温变形过程中必然的物理冶金学现象。本文在查阅大量文献资料的基础上(大部分是英文文献),根据国内外研究现状,确定将“超低碳钢铁素体低温变形行为研究”作为研究方向,研究内容包括:变形工艺参数对超低碳钢铁素体变形时流动应力的影响、变形过程中的动态再结晶、道次间的静态再结晶等,以期为超低碳钢铁素体低温变形在我国钢铁工业生产中的应用、变形工艺参数的合理制定等提供理论依据。同时丰富我国在这一领域的理论研究成果。本研究采用理论研究与实验研究相结合的方法,选择武汉钢铁公司实际生产的一种超低碳Ti-IF钢作为研究对象,在理论分析和热模拟实验的基础上,比较系统、全面地研究了该钢种的铁素体低温变形行为,得到了以下几个主要结论。(1)超低碳IF钢铁素体低温变形时,变形工艺参数对流动应力的影响呈现出与奥氏体区高温变形不同的特征,在分析影响流动应力因素的基础上,本文经过理论推导,得到适用于超低碳钢铁素体低温变形条件的新的流动应力本构模型,并在热模拟实验的基础上,建立了超低碳IF钢铁素体低温变形条件下的流动应力本构方程。这个研究结果是本文的主要内容之一,也是本研究的创新点之一。更多还原

【Abstract】 Ferrite deformation of steels at warm temperature is a new production technology, which is suitable to produce low carbon(LC) and ultra low carbon steels(ULC).The researchers in foreign countries began research on the low temperature processing in ferrite region of ULC many years ago and their researches involved many different fields, including influences of deformation technology schedule on product microstructure and properties, dynamic recrysterllization and static recrysterllization during deformation and deep drawing property of products, influences of microalloy elements on microstructure and properties of deformed metals etc. At the same time, this new technology of processing steels has been successfully used in the production of ultra thin strip and deep drawable steels. But the researches in this field in China began very late and research fields are very few. About 10 research papers published so far mainly dealt with the texture of products under the condition of ferrite deformation of ULC at warm temperature. In general, so far there have been few papers about basic deformation behaviors of ULC, such as flow stress model, dynamic recrysterllization and static recrysterllization during ferrite processing of ULC. Corresponding to this situation, this new metal processing technology has not been used in the production of steels in China.Changing the deformation temperature from the“hot”to“warm”or“low temperature”regime leads to a considerable change in the physical metallurgy. During, or before, ferrite deformation (warm deformation), the workpiece undergoes a transformation from the austenite phase to the ferrite phase. This change in structure has a significant impact on the product metallurgy both during and after forming. The transformation and recrysterllization of ferrite are therefore an integral part of the physical metallurgy of ferrite (warm) deforamtion.According to the research situation in foreign countries and in China,“The Researches on Deformation Behaviors of Ferrite Processing of Ultra Low Carbon Steels at Low Temperature”was selected as the research item on the basis of reading a lot of research literature. The influences of deformation technology parametres on flow stress , dynamic recrysterllization and static recrysterllization during ferrite deformation of ULC etc are included in the research in this dissertation. The purposes of research in the dissertation are to provide the theoretical basis for deciding the suitable更多还原