CFETR真空室焊接接头力学性能分析

Mechanical Properties of Welded Joints in Vacuum Chamber of Nuclear Fusion Reactor:A Simulation and Experimental Study

研究分析了中国聚变工程实验堆(CFETR)对真空室焊接的焊缝接头机械性能要求及本征特点,应用ANSYS软件建立了考虑热影响区的焊接接头有限元模型,数值分析了焊接接头结构参数与接头整体力学性能的关系,并基于窄间隙鸭极氮弧焊制作了焊接试件,进行了性能测试和显微组织形貌实验。结果表明,试件未出现热裂纹和未熔合等缺陷;窄间隙钩极氮弧焊热输入较小,热影响区晶粒长大不明显,未出现明显软化,其宽度对提高焊接接头整体强度影响最大。阐释了焊接接头结构的力学特征及形成机制,为聚变堆真空室焊接接头结构设计和焊接工艺的优化提了供理论依据。

We addressed the narrow gap tungsten inert gas(NG-TIG)welding of the vacuum chamber of Chi na fusion engineering test reactor(CFETR)assembled with 32 pieces of 316L Austenitic stainless-steel.The me chanical properties of welded joints,especially in heat affected zone(HAZ),was mathematically modeled,theoreti cally analyzed and numerically simulated with ANSYS and experimentally evaluated.The influence of the welding conditions on the mechanical behavior was investigated with conventional mechanical probes for welding optimiza tion.The sample joints welded under optimized conditions meet the stringent requirements of fusion reactor.For ex ample,no obvious defects,including hot-cracks,incomplete fusion,voids and pores existed;the small heat input little affected the softening and grain growth in HAZ,though HAZ width has a major impact on overall strength of welded joint.We suggest that the results be of some technological interest in welding vacuum chamber of fusion reactor.