宽薄船板组织性能和焊接接头残余应力特征研究

Study of Microstructure andProperties of Wide and Thin Ship Plates and Residual Stress Characteristics of welded joints

采用金相、扫描电镜和超声波残余应力检测仪等研究了低碳(0.10%C)和中碳成分设计(0.16%C)钢质薄板的组织结构和力学性能及激光焊焊板的残余应力分布特征。研究结果表明,钢板的热轧组织均由铁素体和珠光体构成,低碳成分钢板的珠光体含量低于中碳成分,铁素体晶粒尺寸小于后者,二者强度水平相当。激光焊焊板中的残余应力沿焊缝中心区域基本呈对称分布,低碳钢质薄板焊板中存在向母材区随机延伸的较高残余应力。在相似强度水平下,中碳成分钢质薄板有利于内应力和焊接变形控制。

The microstructure,mechanical properties of thin steel plates of low-carbon(0.10%C)and medium-carbon composition(0.16%C)design and the residual stress distribution characteristics of laser welded plates were investigated using metallography,scanning electron microscope and ultrasonic residual stress detector equipment.The research results show that the hotrolled microstructure of steel plates is composed of ferrite and pearlite,and the pearlite content of low-carbon composition steel plates is lower than that of medium-carbon composition,and the ferrite grain size is smaller than that of the latter,the strength levels of both are comparable.The residual stresses in the laser welded plate are basically symmetrically distributed along the central region of the weld,and there are higher residual stresses in the low-carbon thin steel plate that extend randomly toward the base material area.At similar stress levels,thin steel plates of medium-carbon composition are beneficial for internal stress and weld deformation control.