镀镍碳钢与304不锈钢扩散焊接及复合薄板的力学性能

发布时间：2018-04-08 15:45

本文选题：不锈钢复合板　切入点：扩散焊接　出处：《武汉科技大学》2016年硕士论文

【摘要】：不锈钢-碳钢复合板能够降低不锈钢的用量,具有耐蚀性与良好的力学性能,适用于腐蚀环境的结构构件中。目前,不锈钢复合板的制备方法主要为爆炸法与轧制法,但是都有各自的缺陷。关于不锈钢复合板的研究主要集中于焊接接头组织与强度,而对复合板的整体性能关注极少。扩散焊接对于材料的复合是一种有效的焊接技术,特别适用于物化性能迥异的材料之间的复合。本文以碳钢为基层材料,不锈钢为覆层材料,采用双面复合的形式,通过扩散焊接法对碳钢与304不锈钢进行焊接,并结合轧制与热处理工艺得到不锈钢复合薄板,研究了热处理与碳钢厚度占比对复合板性能的影响。扩散焊接实验表明,所有焊接试样的界面都呈现为相似的微观结构,碳原子由碳钢向不锈钢的扩散形成了Cr_(23)C_6在不锈钢侧析出,并在碳钢侧留下脱碳区。扩散焊接过程中,加热温度、保温时间、中间层Ni的厚度、碳钢碳含量仅影响脱碳层与碳化物析出区的生长速率而不影响其显微组织,可以通过改变各参数来调整扩散影响区各区域的范围。所得扩散焊接复合板热轧开裂但是能够进行冷轧。研究了热处理对碳钢-304不锈钢复合板组织与拉伸性能的影响,结果表明可以对所得不锈钢复合板进行常规热处理,但是无法消除碳钢侧的脱碳层。其最佳热处理制度为淬火+低温回火,得到复合板截面组织为表面奥氏体+心部回火马氏体。研究了碳钢厚度占比对碳钢-304不锈钢复合板拉伸性能的影响,发现在当前实验条件下,复合板的强度可以表示为各组元厚度占比与强度值乘积的和。
[Abstract]:The composite plate of stainless steel and carbon steel can reduce the amount of stainless steel, and has good corrosion resistance and mechanical properties, so it is suitable for structural members in corrosion environment.At present, the main preparation methods of stainless steel clad plate are explosive method and rolling method, but each has its own defects.The research on stainless steel clad plate is mainly focused on the microstructure and strength of welded joints, but little attention is paid to the overall properties of the composite plate.Diffusion welding is an effective welding technology for the composite of materials, especially for the composites with different physical and chemical properties.In this paper, carbon steel is used as base material and stainless steel as cladding material. In this paper, carbon steel and 304 stainless steel are welded by diffusion welding method, and stainless steel composite sheet is obtained by means of rolling and heat treatment.The effect of heat treatment and the ratio of carbon steel thickness on the properties of composite plate was studied.The results of diffusion welding show that the interface of all the specimens shows a similar microstructure. The diffusion of carbon atoms from carbon steel to stainless steel results in the precipitation of Cr_(23)C_6 on the side of stainless steel and the decarbonization zone on the side of carbon steel.During diffusion welding, heating temperature, holding time, thickness of Ni in middle layer, carbon content of carbon steel only affect the growth rate of decarburized layer and carbide precipitation zone, but not its microstructure.The range of diffusion affected areas can be adjusted by changing the parameters.The resulting diffusion welded composite plate is hot rolled but can be cold rolled.The effect of heat treatment on the microstructure and tensile properties of carbon steel-304 stainless steel clad plate was studied. The results showed that conventional heat treatment could be carried out on the stainless steel clad plate, but the decarburization layer on the side of carbon steel could not be eliminated.The optimum heat treatment is quenching and tempering at low temperature, and the cross section structure of composite plate is surface austenite core tempered martensite.The effect of the ratio of thickness of carbon steel on the tensile properties of carbon steel 304 stainless steel composite plate is studied. It is found that the strength of the composite plate can be expressed as the sum of the product of the component thickness ratio and the strength value under the present experimental conditions.
【学位授予单位】：武汉科技大学
【学位级别】：硕士
【学位授予年份】：2016
【分类号】：TG453.9

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