论文部分内容阅读
本文从热力学的活度概念出发,讨论了异种钢焊接接头的碳迁移现象。除接头两侧化学成分差别外,着重指出不同晶体结构对碳迁移有很大影响,强调了相变过程对碳迁移的重要作用。根据一些异种钢接头碳迁移的特点,将碳迁移过程分为两类:第一类是在焊接高温极短时间内发生的,析出先共析铁素体是发生强烈碳迁移的主要条件;第二类是在相对低的温度长时间内发生的,铬等强烈形成碳化物元素的扩散速度是影响碳迁移过程的主要环节。为抑制这两类碳迁移,从热力学和动力学两方面考虑,提出了具体措施。
Based on the concept of thermodynamic activity, this paper discusses the carbon migration of dissimilar steel welded joints. In addition to the difference in chemical composition on both sides of the joint, it is emphasized that different crystal structures have a great influence on carbon migration, emphasizing the important role of the phase transformation on carbon migration. According to the characteristics of carbon transfer of some dissimilar steel joints, the carbon migration process is divided into two types: the first one occurs within a very short period of welding temperature, the pro-eutectoid ferrite is the main condition for strong carbon migration; The second is at a relatively low temperature for a long time to occur, chromium and other carbide-forming elements of the diffusion rate is the main part of the process of carbon migration. In order to restrain these two kinds of carbon migration, from the aspects of thermodynamics and kinetics, concrete measures are put forward.