X80管线钢焊接接头微区材料力学性能研究

Mechanical properties of micro-zone materials of X80 pipeline steel welded joints

焊接过程中,焊接接头处材料经受复杂的焊接热循环,致使不同区域的组织和性能有较大的差异。介绍微剪切试验和维氏硬度试验两种测试微区材料力学性能的方法,并分析其各自的优缺点。采用这两种方法对X80管线钢焊接接头不同区域材料进行力学性能测试,并对试验结果进行分析比较。研究表明,微剪切试验能够直观、定量、连续地描述整个非均质区域的强度和塑性分布,适合研究材料的局部力学性能,特别是评定焊接接头微区材料的力学性能;采用微剪切试验方法测定微区材料的力学性能更为准确可靠。

During welding process,the materials at the welded joints undergo a complex welding thermal cycle,which results in great differences in the microstructure and properties of different regions.Two methods to measure the mechanical properties of micro-zone materials,i.e.micro-shear test and Vickers hardness test,are introduced,and their advantages and disadvantages are analyzed.Using these two methods,the mechanical properties of different micro-zones of X80 pipeline steel welded joint were determined and the testing results were compared.The research shows that the micro-shear test can intuitively,quantitatively and continuously describe the strength and plasticity distributions of all heterogeneous zones,and is suitable for researching the local mechanical properties of the material,especially for assessing the mechanical properties of the micro-zone material of welded joint.Using micro shear test method for determination the mechanical properties of micro-zone material is more accurate and reliable.