高强钢L485MB+316L双金属复合管对接焊工艺验证

针对高强钢L485MB+316L双金属复合管钢级的的提升、尺寸增大，导致传统的手工氩弧焊打底+焊条电弧焊填充盖面焊接方法无法满足其焊接需求的问题，分析了L485MB+316L双金属复合管材料的化学成分和力学性能，从焊材选择以及工艺参数等角度制定了详细的对接焊焊接工艺，并根据标准对焊口试样进行了拉伸试验、弯曲试验、刻槽锤断试验和腐蚀试验。结果表明，316L内衬管采用316L药芯焊丝焊接后的耐腐蚀性能可以满足API 5LC标准中对耐蚀合金的要求；作为耐蚀合金钢与碳钢的过渡区域采用ER309L焊材可以有效连接不锈钢与碳钢，且能保证过渡区域的良好韧性；采用JM-68作为填充盖面金属可以有效地满足X70级钢的强度要求。

Butt Welding Process Verification of High Strength Steel L485MB+316L Bimetal Composite Pipe

With steel upgrading and size enlarging of high strength steel L485MB+316L bimetal composite pipe, it brought about the traditional welding method of manual TIG backing welding + shielded metal arc welding, filling and covering cannot meet the welding requirements. In this article, it analyzed the chemical composition and mechanical properties of L485MB+316L bimetal composite pipe, formulated detailed butt welding process from selecting welding material and welding parameters etc. According to standard requirements to conduct a series of tests, including tensile test, bending test, DWTT and corrosion test. The results indicated that the corrosion resistance of 316L lining tube using 316L flux-cored wire welding can meet API 5LC standard requirements for corrosion resistant alloy; As the transition zone between the corrosion resistant alloy steel and carbon steel, using ER309L consumable can effectively bond stainless steel and carbon steel, and can guarantee the good toughness of transition zone. Using JM-68 as filling covering metal can effectively meet the requirements of X70 grade steel strength.