【摘要】 以Z81作为钎料,对碳的质量分数分别为5.40%、5.45%、5.50%的WC-8%Co硬质合金与1Cr13不锈钢进行高频感应钎焊。通过OM、SEM分析了钎焊接头的微观组织,并对其力学性能进行了分析,同时采用ANSYS对钎焊接头残余应力进行了模拟。研究表明:在焊接过程中,碳含量对钎焊接头微裂纹的产生、接头处硬质合金的硬度、断裂韧性和强度产生影响。当碳的质量分数为5.40%和5.50%时,在硬质合金与焊缝的界面处出现焊接微裂纹;不同碳含量的硬质合金其硬度均随着与焊缝距离的减小而减小;三种碳含量的硬质合金的断裂韧性均在距焊缝300μm处急剧下降,但其中碳的质量分数为5.45%时的硬质合金下降幅度最小且此碳含量下钎焊接头抗弯强度达到最大值458 MPa。通过ANSYS模拟得出硬质合金与钢焊接的残余应力在垂直焊缝方向上呈梯度分布,最大值出现在硬质合金与焊缝界面处。本实验中,硬质合金碳的质量分数为5.45%时具有最佳的焊接性能。更多还原

【Abstract】 WC-8%Co cemented carbide with different carbon content, i.e. 5.40%, 5.45%, 5.50%, were brazed on 1Cr13 stainless steel with brazing filler metal of Z81 by high-frequency induction. The microstructure of the brazing joint was observed by OM and SEM. The properties of the brazing joint were tested. Additionally, the residual stress and its distribution in the joint were simulated by ANSYS. The results show that the generation of the weld crack, micro hardness,fracture toughness and bending strength of the joint are affected by the carbon content of the cemented carbide during welding. It is found that microcracks appear in the weld joint when the carbon content in the cemented carbide is 5.40wt%and 5.50wt%. The hardness of all the cemented carbide in the direction perpendicular to the weld joint decreases with the reducing of the distance from the weld joint. The fracture toughness of all the specimens sharply drops at the distance of 300μm away from the weld joint, when the carbon content is 5.45wt% the descend range is smallest, at the same time the bending strength of the joint has the maximum value of 458 MPa. The residual stress shows gradient distribution in the direction perpendicular to the weld joint by ANSYS, and the maximum value exists at the interface of the cemented carbide and the filler metal layer. In this experiment the brazing property of the cemented carbide is the best when the carbon content is 5.45wt%.更多还原