【摘要】 通过拉伸、疲劳和金相检验试验,对S355J2W耐候钢、空冷状态焊接接头和退火状态焊接接头进行了显微组织和力学性能的研究.结果表明:两种状态焊接接头的力学性能都达到了要求,S355J2W耐候钢退火状态焊接接头的强度低于空冷状态焊接接头的强度;退火状态焊接接头的塑性好于空冷状态焊接接头的塑性;退火状态焊接接头的疲劳寿命低于空冷状态焊接接头的疲劳寿命;退火状态焊接接头与空冷状态焊接接头相比,每个区域的晶粒都有明显的细化和均匀化,空冷状态的焊接接头显微组织的晶界比较清晰.更多还原

【Abstract】 In present work,the welded joints processed from S355J2W steel were treated separately by air cooling and annealing.The investigation of the microstructure and mechanical properties of the welded joints were conducted through the tensile test,fatigue test and metallographic examination.The results showed that the mechanic properties of the welded joints after both heat treatments had achieved the requiring standard.Compared to the welded joint treated by air cooling,the annealed welded joint exhibited better plasticity,accompany with poorer strength.Through the fatigue test,it was revealed the air cooled welded joint had comparatively longer fatigue life-time than the annealed one.The microstructure observation showed that the grain of all areas in annealed welded joint appeared more significant reduction in size and clearer homogenization,compared to the air cooled joint.Meanwhile,the grain boundary in air cooled welded joint was easier to observe than the annealed joint.更多还原