采用裂纹尖端张开位移(Crack tip opening displacement,CTOD)试验方法对X52钢水下等静压摩擦圆锥塞焊接头的断裂行为进行试验研究,探讨了焊后热处理温度对接头不同位置的微观组织及断裂韧性的影响。结果表明,由于焊缝中心产生明显不均...采用裂纹尖端张开位移(Crack tip opening displacement,CTOD)试验方法对X52钢水下等静压摩擦圆锥塞焊接头的断裂行为进行试验研究,探讨了焊后热处理温度对接头不同位置的微观组织及断裂韧性的影响。结果表明,由于焊缝中心产生明显不均匀淬硬马氏体及少量魏氏组织,焊态下焊缝中心CTOD平均值仅为0.103 mm,明显低于母材断裂韧性。随着焊后热处理温度从500℃增加到800℃,焊缝中心区域不均匀淬硬组织转变为回火组织并趋于均匀化,这使得焊缝中心区域抗断能力获得有效提高;在800℃热处理后焊缝中心CTOD平均值可达到0.8 mm以上。但由于结合区中夹杂物的存在,经适当温度的焊后热处理后,焊缝结合区断裂韧性的提高仍非常有限,800℃热处理后结合区CTOD值最高可达到0.3 mm。接头结合区的抗断裂能力是影响水下摩擦圆锥塞焊修复技术应用的关键因素。展开更多
The purpose of this study is to reveal the microstructure and mechanical properties of friction stir welding(FSW)joints prepared in water/air.For comparable analysis,the submerged FSW(SFSW)and conventional FSW are bot...The purpose of this study is to reveal the microstructure and mechanical properties of friction stir welding(FSW)joints prepared in water/air.For comparable analysis,the submerged FSW(SFSW)and conventional FSW are both conducted on 6061-T6 aluminum alloy plates at the combination rotation speed of 800 r/min and the traverse rate of 50 mm/min.The results show that a greatest grain refinement is achieved by SFSW,which is remarkably smaller than that of the base material(BM)and air FSW(AFSW)samples,leading to a significant improvement of tensile strength from 202.5 MPa in the AFSW sample to 232 MPa in the SFSW sample.展开更多
文摘The purpose of this study is to reveal the microstructure and mechanical properties of friction stir welding(FSW)joints prepared in water/air.For comparable analysis,the submerged FSW(SFSW)and conventional FSW are both conducted on 6061-T6 aluminum alloy plates at the combination rotation speed of 800 r/min and the traverse rate of 50 mm/min.The results show that a greatest grain refinement is achieved by SFSW,which is remarkably smaller than that of the base material(BM)and air FSW(AFSW)samples,leading to a significant improvement of tensile strength from 202.5 MPa in the AFSW sample to 232 MPa in the SFSW sample.
