X65管线钢对接接头的疲劳性能

Fatigue properties of X65 pipie-line steel butt joints

摘要: 试验表明,焊接结构的疲劳裂纹主要起源于接头焊趾处,因此合理地处理焊接接头焊趾可改善其疲劳性能。超声冲击处理是一种通过改变焊趾区几何形状、消除焊趾缺陷以及调整焊趾区残余应力场来改善焊接接头及结构疲劳强度的有效方法。利用自行研制的超声冲击装置对X65钢焊接对接管接头实施了处理,然后进行了焊态、超声冲击处理态及母材的疲劳对比试验。结果表明,X65钢焊接对接管接头焊态疲劳强度△σ(2×10⁶)为219 MPa;母材的疲劳强度△σ(2×10⁶)为338 MPa;超声冲击处理后接头的疲劳强度△σ(2×10⁶)为302 MPa。

Abstract: Ultrasonic peening is an efficient method to improve the fatigue strength of welded joints and suchlike structures by bettering the geometry, removing the defects and adjusting residual stress field of the weld toes. The welded joints of X65 steel were peened by the homemade ultrasonic peening device, then we compared the fatigue strength of as welded, peened after welding and base metal. The test results show: the fatigue strength:Δσ(2×10⁶) 219 MPa as welded, Δσ(2×10⁶) 338 MPa as base metal, Δσ(2×10⁶)302 MPa as peened.