圆柱形容器环缝错边的安全性评价

环焊缝就是一锥形环,可以建立其数学模型,进而证明了焊缝错边缺陷是可以修复的。通过应力计算分析和实验验证可以得出:当b/s较小(b/s<0.2)时,错边可以用磨削方法进行修复;当b/s较大时,可用堆焊方法进行修复,且堆焊宽度H不超过100mm。同时,在控制应力水平不超过1.5[σ]时,错边量和角变形量的和可以允许在不超过0.7s的范围内。研究及安全性评价表明ASME,GB150等标准对环焊缝的控制过于严格,也给压力容器制造企业增加了成本。因此,建议GB150放宽对B类焊缝错边量的控制要求。

Safety Assessment on Cylindrical Vessel''''s Girth Welding Disalignment

Girth welding is simply cone-shaped welding; its disalignment can be restored by establishing mathematical model. With stress calculation analysis and experimental verification, it could be concluded that when b/s is small (<0.2), the disalignment could be restored by polishing. When greater, by repair welding with width (H) no more than 100mm. Meanwhile, when controlling stress level is <1.5σ, allowable value of disalignment and angle deformation could be <0.7s. All these indicates that the standards stipulated in ASME and GB150 are too strict for girth welding control, and the cost of pressure vessel manufacturers will consequently rise. It suggests that the restriction on Type B girth welding disalignment in GB150 should be revised.