焊接時(shí)由于管件結(jié)構(gòu)尺寸和形狀的限制,，雙面焊接有時(shí)是不可能的,。只能開單面坡口的特殊操作方法是單面焊雙面的技術(shù),，這是手工電弧焊的一項(xiàng)高難度操作技能,。

Due to the limitation of pipe structure size and shape, double-sided welding is sometimes impossible. The special operation method of only one side groove is the technology of one side welding and two sides, which is a difficult operation skill of manual arc welding.

立焊時(shí),，在重力作用下,，由于熔池溫度過高，被覆焊條熔化形成的熔滴與熔池中的鐵水容易滴落形成焊瘤,，焊縫兩側(cè)形成咬邊,。

During vertical welding, due to the high temperature of the molten pool under the action of gravity, the molten droplets formed by the melting of the covered electrode and the molten iron in the molten pool are easy to drip to form weld beading, and undercut is formed on both sides of the weld.

溫度過低時(shí),，容易出現(xiàn)夾渣，反面容易形成未焊透,、焊瘤等缺陷,，造成焊縫成型困難。

When the temperature is too low, slag inclusion is easy to occur, and defects such as incomplete penetration and weld beading are easy to form on the reverse side, resulting in difficulty in weld forming.

熔池的溫度不容易直接識(shí)別,，但與熔池的形狀和大小有關(guān),。因此，在焊接過程中,，通過仔細(xì)觀察和控制熔池的形狀和大小,，可以達(dá)到控制熔池溫度和保證焊接質(zhì)量的目的。

The temperature of molten pool is not easy to identify directly, but it is related to the shape and size of molten pool. Therefore, in the welding process, by carefully observing and controlling the shape and size of the weld pool, the purpose of controlling the weld pool temperature and ensuring the welding quality can be achieved.

根據(jù)老師傅十幾年的經(jīng)驗(yàn),，總結(jié)出以下規(guī)律：

According to the experience of teacher Fu for more than ten years, the following rules are summarized:

焊條角度很重要,，焊接規(guī)范不可或缺。

Electrode angle is very important and welding specification is indispensable.

在垂直焊接過程中,，由于焊條熔化形成的熔滴,，熔池中的鐵水容易滴下形成焊瘤,，以及焊縫兩側(cè)的咬邊,，焊縫的成形變差。掌握正確的焊接規(guī)范,，根據(jù)焊接條件的變化,，調(diào)整焊條角度及運(yùn)條的速度。

In the process of vertical welding, due to the droplets formed by the melting of the electrode, the molten iron in the molten pool is easy to drop and form weld beading, as well as the undercut on both sides of the weld, the weld formation becomes worse. Master the correct welding specification, adjust the electrode angle and the speed of electrode transportation according to the changes of welding conditions.

焊條與焊件表面的左右夾角為90度,，開始焊接時(shí)與焊縫的夾角為70 ~ 80度,，中間為45 ~ 60度，完成焊接時(shí)為20 ~ 30度,。裝配間隙為3 ~ 4毫米 ,，應(yīng)選擇較小的焊條直徑 3.2毫米 ，使用較小的焊接電流,，打底焊為110~115A,，中間過渡層為115~120A，覆蓋層為105~110A,。

The included angle between the electrode and the surface of the weldment is 90 degrees, the included angle between the electrode and the weld is 70 ~ 80 degrees at the beginning of welding, 45 ~ 60 degrees in the middle, and 20 ~ 30 degrees at the completion of welding. The assembly gap is 3 ~ 4mm, the smaller electrode diameter of 3.2mm shall be selected, and the smaller welding current shall be used. The backing welding is 110 ~ 115a, the intermediate transition layer is 115 ~ 120a, and the covering layer is 105 ~ 110A.

一般電流比平焊小12％ ~ 15％,，以減小熔池體積，減少重力影響,，利于熔滴過量,。采用短弧焊接，縮短熔滴到熔池的距離,，形成短路過渡,。

Generally, the current is 12% - 15% less than that of flat welding, so as to reduce the volume of molten pool and the influence of gravity, which is conducive to excessive droplet. Short arc welding is adopted to shorten the distance from droplet to molten pool and form short-circuit transition.