固溶处理对00Cr25Ni7Mo3N双相不锈钢超塑性和连接性能的影响

采用不同固溶工艺处理后的00Cr25Ni7Mo3N双相不锈钢,在恒温的热拉伸试验机上进行超塑性测试,通过Gleeble3500热模拟试验机进行超塑性扩散连接实验研究,并采用扫描电镜对固溶处理金相及连接试样界面孔洞进行观察.结果表明,由于固溶处理温度不同,α相和γ相体积比(xα/xγ)不同.超塑性拉伸测试中,在同一变形条件下,随着初始xα/xγ的增大,延伸率和峰值应力相应增大.固溶温度为1350℃的试样,在960℃、1×10-3s-1条件下拉伸,延伸率达到1186%;超塑性扩散连接在1100℃温度下进行时,压力加载形式不同,扩散连接界面结合机理不同,但加载形式对试样的界面剪切强度影响不大.在连接过程中,界面孔洞闭合情况和滞留位置与晶界迁移的相对速度有关.

Effect of solution treatment on the super plasticity and bonding property of 00Cr25Ni7Mo3N duplex stainless steel

00Cr25Ni7Mo3N duplex stainless steel was treated by different solutions,its super plastic deformation was tested on an isothermal tensile machine,and the diffusion bonding by super plastic deformation was performed on a Gleeble 3500 thermal simulator.The solution treated microstructures and the bonding interface voids were observed by scanning electron microscopy(SEM).The results indicate that the volume ratio of α phase to γ phase(xα/xγ) varies with the solution temperature.During the tensile process,the elongation and the peak stress increase with the initial value of xα/xγ increasing under the same deformation condition.The elongation of the specimen solution-treated at 1 350 ℃ reaches to 1 186% at a deformation temperature of 960 ℃ and a strain rate of 1×10-3s-1.At a bonding temperature of 1 100 ℃ the diffusion bonding mechanism depends on loading modes,but the influence of loading modes on the interfacial shear strength is not significant.During the bonding,the closure degree and retention position of the interfacial voids are related with the relative migration velocity of grain boundaries.