基于DIC技术获取焊接接头单轴拉伸力学性能

The Uniaxial Tensile Mechanical Properties of Welded Joints Obtained Based on the DIC Technology

目的获取异种金属焊接接头局部拉伸力学性能。方法针对压水堆核电机组蒸汽发生器接管与安全端异种金属焊接接头(Dissimilar metal weld joint,DMWJ,其接管材料为20MND 5低合金钢,安全端为Z2 CND 18.12控氮奥氏体不锈钢,焊缝材料为INCONEL 52镍基合金),采用等直圆棒拉伸试验获得蒸汽发生器接管材料20MND 5的单轴拉伸应力-应变关系,基于数字图像相关(Digital image correlation,DIC)技术,采用平板拉伸试验获取DMWJ单轴拉伸力学性能。结果20MND 5的弹性模量和屈服强度分别为197 GPa和498 MPa。与20MND 5单轴拉伸应力-应变关系对比,DMWJ单轴拉伸过程中母材及焊缝位置的全场应变,及DMWJ母材和焊缝位置局部的单轴拉伸力学性能,二者完全吻合。结论DIC技术可精确测量DMWJ局部单轴应力-应变关系,对于三代压水堆核电站DMWJ的设计、安全评定及寿命管理具有重要意义。

The purpose of this paper is to obtain the part of tensile mechanical property of dissimilar metal weld joint.For the Taishan III nuclear power plant steam generator nozzle and the safe end to nozzle dissimilar metal weld joint(DMWJ,which nozzle material is 20MND 5 low-alloy steel,the safety end is Z2 CND 18.12 nitrogen-controlled austenitic stainless steel,and the weld material is INCONEL 52 nickel-based alloy),the uniaxial tensile stress-strain relationship of the steam generator nozzle material 20MND 5 was obtained by the isometric round bar tensile test.The DMWJ uniaxial tensile test was obtained by the flat plate tensile test.mechanical properties based on the Digital Image Correlation(DIC)technology.The elastic modulus and yield strength of 20MND 5 are 197 GPa and 498 MPa,respectively.Full-field strain of base metal and weld in DMWJ uniaxial tensile process is consistent with uniaxial tensile properties of DMWJ base metal and local weld positions by comparing with the uniaxial tensile stress-strain relationship of 20MND 5.Therefore,it can be concluded that it is helpful by using the DIC technology to accurately measure the uniaxial stress-strain relationship of the DMWJ,which can be of a great significance for the design,safety assessment and life management of the third-generation pressurized water reactor nuclear power plant.