In the welding process, there are many matters needing attention. Once neglected, it may make a big mistake.

1、焊接施工不注意选择电压

1. Welding construction does not pay attention to the selection of voltage

【现象】焊接时无论是打底、填充、盖面，不管坡口尺寸大小，均选择同一电弧电压。这样有可能达不到要求的熔深、熔宽，出现咬边、气孔、飞溅等缺陷。

[phenomenon] during welding, the same arc voltage shall be selected for priming, filling and covering, regardless of groove size. In this way, the required penetration depth and width may not be reached, and defects such as undercut, air hole and splash may appear.

【措施】一般针对不同情况应该分别选择相应长弧或短弧能得到较好的焊接质量和工作效率。

[measures] generally, the corresponding long arc or short arc should be selected according to different situations, so as to obtain better welding quality and work efficiency.

2、焊接不控制焊接电流

2. Welding does not control welding current

【现象】焊接时，为了抢进度，对于中厚板对接焊缝采取不开坡口。强度指标下降，甚达不到标准要求，弯曲试验时出现裂纹，这样会使焊缝接头性能不能保证，对结构构成潜在危害。

[phenomenon] during welding, in order to speed up the progress, no groove is adopted for the butt weld of medium and thick plate. The strength index decreases, even fails to meet the standard requirements, and cracks appear during bending test, which will make the performance of weld joint unable to be guaranteed and pose potential harm to the structure.

【措施】焊接时要按工艺评定中的焊接电流控制，允许有10～15%浮动，坡口的钝边尺寸不宜超过6mm。对接时，板厚超过6mm时，要开坡口进行焊接。

[measures] the welding shall be controlled according to the welding current in the process qualification, 10 ~ 15% floating is allowed, and the blunt edge size of the groove shall not exceed 6mm. During butt joint, when the plate thickness exceeds 6mm, groove shall be made for welding.

3、不注意焊接速度与焊接电流，焊条直径协调使用

3. Do not pay attention to the coordinated use of welding speed, welding current and electrode diameter

【现象】焊接时不注意控制焊接速度与焊接电流，焊条直径、焊接位置协调起来使用。

[phenomenon] when welding, do not pay attention to controlling the welding speed and welding current, and coordinate the use of electrode diameter and welding position.

如对全熔透的角缝进行打底焊时，由于根部尺寸窄，如焊接速度过快，根部气体、夹渣没有足够的时间排出，易使根部产生未熔透、夹渣、气孔等缺陷；盖面焊时，如焊接速度过快，也易产生气孔；焊接速度过慢，则焊缝余高会过高，外形不整齐；焊接薄板或钝边尺寸小的焊缝时，焊接速度太慢，易出现烧穿等情况。

For example, when backing welding the full penetration corner seam, due to the narrow size of the root, such as the welding speed is too fast, the root gas and slag inclusion do not have enough time to be discharged, which is easy to produce defects such as incomplete penetration, slag inclusion and pores at the root; During cover welding, if the welding speed is too fast, it is also easy to produce pores; If the welding speed is too slow, the weld reinforcement will be too high and the shape will be irregular; When welding thin plates or welds with small blunt edge size, the welding speed is too slow and it is easy to burn through.

【措施】焊接速度对焊接质量和焊接生产效率有重大影响，选用时配合焊接电流、焊缝位置（打底焊，填充焊，盖面焊）、焊缝的厚薄、坡口尺寸选取适当的焊接速度，在保证熔透，气体、焊渣易排出，不烧穿，成形良好的前提下选用较大的焊接速度，以提高生产率效率。

[measures] the welding speed has a significant impact on the welding quality and welding production efficiency. When selecting, the appropriate welding speed shall be selected in combination with the welding current, weld position (backing welding, filler welding, cover welding), weld thickness and groove size. On the premise of ensuring penetration, easy discharge of gas and welding slag, no burn through and good forming, the larger welding speed shall be selected to improve the productivity and efficiency.

4、施焊时不注意控制电弧长度

4. The arc length is not controlled during welding

【现象】施焊时不根据坡口形式、焊接层数、焊接形式、焊条型号等适当调整电弧长度。由于焊接电弧长度使用不当，较难得到高质量的焊缝。

[phenomenon] during welding, the arc length is not properly adjusted according to the groove form, number of welding layers, welding form, electrode model, etc. Due to the improper use of welding arc length, it is difficult to obtain high-quality welds.

【措施】为了保证焊缝质量，施焊时一般多采用短弧操作，但可以根据不同的情况选用合适的弧长以获得更好的焊接质量，如V形坡口对接、角接的一层应使用短些的电弧，以保证焊透，且不发生咬边现象，二层可以稍长，以填满焊缝。焊缝间隙小时宜用短弧，间隙大时电弧可稍长，焊接速度加快。

[measures] in order to ensure the weld quality, short arc operation is generally adopted during welding, but the appropriate arc length can be selected according to different conditions to obtain better welding quality. For example, the first layer of V-groove butt joint and fillet joint should use shorter arc to ensure penetration and no undercut. The second layer can be slightly longer to fill the weld. Short arc should be used when the weld gap is small. When the gap is large, the arc can be slightly longer and the welding speed can be accelerated.