板式换热器用5052铝合金TIG焊接头性能分析

Analysis of performances of 5052 aluminum alloy TIG welded joint in plate heat exchanger

针对板式换热器用1 mm厚5052铝合金薄板的焊接性进行了研究。分别使用3组不同的焊接参数对板材进行焊接试验。为了分析所得焊接接头的力学性能,分别对3组试样进行焊接接头金相组织观察、拉伸试验、弯曲试验及拉伸断口形貌观察。结果表明：在第3组焊接参数（钨极直径2 mm,焊丝ER5356直径1.6 mm,氩气流量15 L/min,焊接电流70 A,焊接速度2.45～2.95 mm/s）下所获得的焊接接头综合力学性能较好,抗拉强度可达母材的92.8%,弯曲角度可达180°,焊缝组织均匀,断口存在大量较深、均匀分布的韧窝。焊接接头中夹杂物是焊接接头力学性能降低的重要因素。

In this paper, it was researched about the weld ability of 1 mm thick 5052 aluminum alloy sheet used in the plate heat exchanger. Using three groups of different welding parameters for welding test of the plank. In order to analyze the mechanical properties of welded joint, respectively on three groups of sample welding joint microstructure observation, tensile test, bending test and the tensile fracture morphology observation. Results showed that when using the third set of welding parameters(tungsten diameter was 2 mm, wire diameter was 1.6 mm, argon flow was15 L/min, welding current was 70 A, welding speed was 2.45 ~2.95 mm/s), it could be obtained that the best mechanical properties of welded joint. Tensile strength could be up to 92.8% of the parent metal, bending angle was180°, the weld microstructure of uniform, there were plentiful deep and uniform distribution of ductile fracture.Impurities that exist in the welded joint were an important factor to reduce mechanical properties of welded joint.