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

1、焊接施工不注意選擇電壓

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

【現象】焊接時無論是打底、填充、蓋面，不管坡口尺寸大小，均選擇同一電弧電壓。這樣有可能達不到要求的熔深、熔寬，出現咬邊、氣孔、飛濺等缺陷。

[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】一般針對不同情況應該分別選擇相應長弧或短弧能得到較好的焊接質量和工作效率。

[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、焊接不控制焊接電流

2. Welding does not control welding current

【現象】焊接時，為了搶進度，對于中厚板對接焊縫采取不開坡口。強度指標下降，甚達不到標準要求，彎曲試驗時出現裂紋，這樣會使焊縫接頭性能不能保證，對結構構成潛在危害。

[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】焊接時要按工藝評定中的焊接電流控制，允許有10～15%浮動，坡口的鈍邊尺寸不宜超過6mm。對接時，板厚超過6mm時，要開坡口進行焊接。

[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、不注意焊接速度與焊接電流，焊條直徑協調使用

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

【現象】焊接時不注意控制焊接速度與焊接電流，焊條直徑、焊接位置協調起來使用。

[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.

如對全熔透的角縫進行打底焊時，由于根部尺寸窄，如焊接速度過快，根部氣體、夾渣沒有足夠的時間排出，易使根部產生未熔透、夾渣、氣孔等缺陷；蓋面焊時，如焊接速度過快，也易產生氣孔；焊接速度過慢，則焊縫余高會過高，外形不整齊；焊接薄板或鈍邊尺寸小的焊縫時，焊接速度太慢，易出現燒穿等情況。

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】焊接速度對焊接質量和焊接生產效率有重大影響，選用時配合焊接電流、焊縫位置（打底焊，填充焊，蓋面焊）、焊縫的厚薄、坡口尺寸選取適當的焊接速度，在保證熔透，氣體、焊渣易排出，不燒穿，成形良好的前提下選用較大的焊接速度，以提高生產率效率。

[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、施焊時不注意控制電弧長度

4. The arc length is not controlled during welding

【現象】施焊時不根據坡口形式、焊接層數、焊接形式、焊條型號等適當調整電弧長度。由于焊接電弧長度使用不當，較難得到高質量的焊縫。

[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】為了保證焊縫質量，施焊時一般多采用短弧操作，但可以根據不同的情況選用合適的弧長以獲得更好的焊接質量，如V形坡口對接、角接的一層應使用短些的電弧，以保證焊透，且不發生咬邊現象，二層可以稍長，以填滿焊縫。焊縫間隙小時宜用短弧，間隙大時電弧可稍長，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.