热处理对低活马氏体钢焊接热影响区的影响
Effect of Heat treatment on CLAM steel welding heat affected zone
沈政
点击：2310次 下载：0次
作者单位：江苏大学材料学院
中文关键字：CLAM钢；热模拟；热处理；显微硬度
英文关键字：CALM steel, thermal simulation, heat treatment, micro-hardness
中文摘要：采用焊接热模拟技术，参照实际焊接工艺，模拟中国低活化马氏体钢（CALM钢）热影响区粗晶区（CGHAZ）热循环过程，并对热模拟后试样进行不同的回火工艺处理。实验发现，CLAM钢热模拟试样经回火处理，碳化物弥散析出，同样的回火工艺条件下，CLAM钢显微组织差异不明显，回火前较高的热量输入导致回火后硬度值更低；在相同的热循环条件下，较高的回火温度，会引起晶粒的显著长大，试样硬度值降低。热模拟试样在较高的温度下回火，可以更为有效的改善CGHAZ区域硬度，随着回火的温度的继续增加，试样硬度趋于平稳。综合考虑回火工艺CALM钢硬度值以及晶粒度的影响，推荐回火温度为760℃到810℃。
英文摘要：Referring to the actual welding process, the thermal simulation technique is used in this paper for simulating the thermal cycling of the coarse grained heat affect zone (CGHAZ) of CLAM steel, then different tempering treatments are proceeded on the samples after simulation. Dispersed precipitation of the carbide is found after the tempering treatment. In the same tempering condition, no obvious differences of microstructure are observed among the tested samples, higher heat input before tempering results in lower hardness after tempering. In the same thermal cycling condition, higher tempering temperature leads to remarkable increase of grain size and decrease of hardness. The hardness of CGHAZ can be effectively improved by tempering the simulated samples at higher temperature and then it changes to be steady with the continue increasing of temperature. Based on the comprehensive consideration of the effect of tempering process on both the hardness and the grain size of CLAM steel, the tempering temperature is advised to be 760℃~810℃.