水下焊条半干式仰焊新工艺

Novel semi-dry type underwater overhead electrode welding technology

关键词:  水下仰焊  焊接成形  金相组织  扩散氢  硬度

Key words:  underwater overhead welding  weld formation  microstructure  diffusion hydrogen  hardness

摘要:

为了克服水下湿法焊条仰焊位置难以施焊的困难,文中提出了一种水下焊条半干式仰焊新工艺,并阐明了该工艺的基本原理和操作方法,且对其焊接工艺性能、焊缝组织、硬度以及扩散氢含量进行了分析. 结果表明,所提出的半干式仰焊工艺可以实现水下焊条仰焊位置焊接,焊缝成形良好,对于直径3.2 mm的水下焊条最佳焊接电流范围为100~140 A,焊接电压为28~32 V;该方法焊缝微观组织主要为侧板条铁素体、针状铁素体和贝氏体,与传统水下湿法焊条焊相比,铁素体的含量增加而贝氏体含量减少;焊接接头最高硬度值和熔敷金属扩散氢含量也明显低于水下湿法焊条焊.

Abstract:

In order to overcome the difficulty of wet-type underwater electrode welding, a novel p semi-dry type underwater overhead welding was proposed. The principle of the process and the operation procedure was clarified it's the welding ability, weld microstructure, hardness and diffusion hydrogen content were studied. The results indicate that this semi-dry overhead welding procedure can be successfully applied in underwater overhead welding position and the appearance of weld is good. The optimum welding current range is 100-140 A for electrode of Φ3.2 mm diameter, the corresponding welding voltage range is 28-32 V. The weld microstructure is mainly composed of ferrite side-plate, needle-like ferrite and bainite. Compared with the traditional underwater wet-type welding, the content of ferrite increased, and the content of bainite decreases accordingly. The highest hardness of welded joints and diffusion hydrogen content in deposited metal are remarkably lower than those of the wet-type underwater electrode welding.