结合实际生产及热处理工艺, 对钻杆焊缝生产检测过程中发现的裂纹成因进行了分析。结果表明: 裂纹均出现在钻杆熔合线附近接头侧外壁, 为淬火过程中内应力较大产生的淬火裂纹。为了解决该问题, 把调质处理的淬火温度降低到Ac1~Ac3, 即对钻杆进行亚温淬火, 再高温回火; 工艺调整后, 在保证产品性能满足技术要求的基础上, 完全避免了焊缝淬火裂纹的产生。

Formation causes of cracks found during drill pipe weld manufacturing inspection process were analyzed combining with the actual manufacture and heat treatment process analysis. The results show that mostly cracks were found at the joint ektexine near the weld line and resulted from the big inherent stress of the quenching process. To resolve this problem, the quench temperature was lowered to Ac1-Ac3, which was equal to subcritical quenching and high-temperature tempering. After adjusting the heat treatment process, the weld quenching cracking could be avoided completely. At the same time, the products performance also well met the technique requirements.