淬火-预拉伸对2A12铝合金厚板残余应力的影响  

Effect of quenching and pre-stretching on residual stresses in 2A12 aluminum alloy thick plates

作　　者：张舒原[1,2] 吴运新[1,2] 廖凯[1,2] 龚海[1,2] 

机构地区：[1]中南大学机电工程学院,湖南长沙410083 [2]高性能复杂制造国家重点实验室,湖南长沙410083

出　　处：《材料热处理学报》2012年第12期47-52,共6页Transactions of Materials and Heat Treatment

基　　金：国家重点基础研究发展规划(2012CB19505);国家重点基础研究发展规划(2010CB731703)

摘　　要：采用层削法对2A12铝合金淬火厚板在预拉伸前后的残余应力进行了测定,厚板的淬火采用阵列喷淋及水浴两种方式。结果表明:两种淬火方式在厚板内部都形成了"内拉外压"的典型分布规律;喷淋方式的淬火强度相对较低,只在厚板靠近表层的地方形成了较大的残余应力,内部靠近中面的位置残余应力水平接近于0;水浴方式淬火强度更大,在厚板整个厚度上形成了单调连续分布的残余应力;预拉伸使喷淋和水浴两种淬火板内的残余应力都大幅度消减;强度更高的淬火工艺加大了板内金属力学性能的不均匀性,减弱了残余应力消减的效果。Residual stresses in quenched and pre-stretched thick plates of 2A12 aluminum alloy were measured by layer removal method. The thick plates were quenched in spray and immersion ways to get different quenching intensities. The results show that plate is cooled down more fast under the immersion-quenching than that of the spray-quenching and residual stress formed under the former circumstance is higher than that of the latter. High level residual stress close to the surface and nearly zero stress around the midplane of the thick plate forms during spraying quenching, while immersion quenching brings monotonical increase of residual stress from surface to the center of the plate. Pre-stretch process significantly reduces the residual stresses in quenched plates. Stress-profile of immersion-quenched plate is changed remarkably while positions of maximum and minimum stress of spray-quenched plate remains roughly unchanged after pre- stretching, indicating that more intensive quenching leads to more inhomogeneity along thickness in the plate.

关 键 词：淬火 预拉伸 2A12 铝合金 残余应力 

分 类 号：TG146.2[一般工业技术—材料科学与工程]