摘 要：本文針对于我厂大型高炉布料气密箱齿轮轴在生产使用过程中出现裂纹或磨损的情况，分析了该轴所用42CrMo钢化学成分以及焊接性能，介绍了42CrMo钢焊接材料的选择，预热及层间温度的选择，以及后热温度的确定，通过对齿轮轴焊接工艺评定试验，证明此次齿轮轴焊接修复工艺以及参数是可行的，最后，总结了焊接过程应注意的问题，为相同应用场合42CrMo钢的焊接提供参考价值。
　　关键词：42CrMo钢 焊接技术 现场焊接
　　Repair Welding Technology of Gear Shaft of Airtight Box of Large Blast Furnace Distribution
　　Yang Qidong Zhao Hui
　　Abstract：This article analyzes the chemical composition and welding performance of 42CrMo steel used in the shaft for the cracks or wear in the production and use of the gear shaft of the airtight box of the large blast furnace distribution box in our factory， and introduces the selection of 42CrMo steel welding materials. The selection of heat and interlayer temperature， as well as the determination of the post-heat temperature， through the gear shaft welding process qualification test， proved that the gear shaft welding repair process and parameters are feasible， and finally， the article summarized the problems that should be paid attention to in the welding process to provide reference value to the welding of 42CrMo steel in the same application situation.
　　Key words：42CrMo steel， welding technology， field welding