45钢和Cr12钢焊接研究.doc

45钢和Cr12钢焊接研究 摘 要 国民经济的迅速发展和科学技术的不断进步，新材料、新工艺的应用日益广泛，对各类工程机械构件的性能提出了更高的要求。在有些情况下，任何一种金属材料都不可能完全满足使用要求，或者即使某种金属比较理想，也往往由于十分稀贵，不能在工程中普遍应用。因此，采用异种金属焊接方法制造复合零部件受到人们的广泛重视，异种金属焊接结构能够最大限度地利用材料的各自优点，具有显著的经济效益。 本课题采用手工电弧焊的方法以及J422焊条焊接45钢和Cr12钢，分析焊接接头的组织和硬度的变化；并对得到的焊接接头进行正火处理，分析热处理前后焊接接头的组织和硬度的变化。试验对比表明：热处理后的焊接接头晶粒明显比未热处理过的要细小，组织结构更加均匀。热处理后焊接接头硬度升高。因此，热处理可以改善焊接接头的组织，并提高其性能。 异种金属的焊接可以节省大量的贵重金属，降低生产的成本，简化结构制造的工艺过程，能够满足如高温强度，耐磨性，耐腐蚀性，低温韧性，磁性等多方面的性能要求。异种钢的焊接除了要研究焊接的一般规律以外，还要研究许多特殊的规律，如异种金属的物理、化学性能和组织结构变化、金属间化合物的形成机理，冶金扩散过程，接头性能的检测等等。掌握和研究异种钢的焊接性是一件十分重要和困难的工作，目前对异种金属焊接中的性能变化仍然是研究的重点。 关键词:异种钢；焊接接头；组织；硬度 页眉分奇数页和偶数页表达不一样 页码的标注，从前言开始到最后算一部分，从新第1页开始算，摘要到清单算一部分 Analysis of the welding Joint for 45 Steel and Cr12 steel Abstract The rapid development of the national economy and science and technology continues to progress, new materials, new technology has been used widely, mechanical components on the performance of various projects and put forward higher requirements. In some cases, any kind of metal materials can not fully meet the requirements, or even if the ideal of a metal, it is often very thin because you can not be widely used in engineering. Therefore, the use of dissimilar metal welding methods to manufacture composite parts are widespread attention, dissimilar metal welding structure to maximize the respective advantages of the use of materials with significant economic benefits. The issue of manual arc welding method and welding electrode J422 45 steel and Cr12 steel, of welded joints and hardness changes in the organization; and welded joints were obtained by normalizing processing, analysis of welded joints after heat treatment and hardness changes. Experimental comparison shows that: the grain of welded joints after heat treatment were significantly higher than without heat treatment had to be small and more uniform structure. Increased hardness of welded joints after heat treatment. Therefore, heat treatment of welded joints can improve the organization and impro