在焊管焊接（jiē）過程中，埋弧（hú）焊也是利用電弧作為（wéi）熱源的焊接方法。埋弧焊（hàn）時電弧是在一層顆粒狀的可熔化焊（hàn）劑覆蓋...埋（mái）弧焊電源一般應具有陡降外特性，可用交（jiāo）流(弧焊變壓器)、直流(弧焊發電機或弧（hú）焊整（zhěng）流器)或交、直流並用。當焊絲確定以後(通常（cháng）取決於所焊的鋼種)，配套用的焊劑則成為關鍵材料，它直接影響焊縫金屬的力學性能(特別是塑性及低溫韌（rèn）性)、抗裂性能、焊接缺陷發生率及焊接生產（chǎn）率等。焊絲（sī）與（yǔ）焊劑的配用重量比為焊絲：焊劑=1.1～1.6，視焊（hàn）接接頭類型、所用焊劑種類（lèi）、焊（hàn）接規範參數而定（dìng）。與熔煉焊劑（jì）相比，燒結焊劑用量較為節省，約可少用20%左右（yòu）。
Submerged arc welding (SAW) is also a welding method using arc as heat source in the welding process of welded pipe. When submerged arc welding, the arc is covered by a layer of granular fusible flux. Submerged arc welding power supply should generally have steep drop characteristics. It can be used in AC (arc welding transformer), DC (arc welding generator or arc welding rectifier) or AC/DC combination. When the welding wire is determined (usually depending on the type of steel being welded), the matching flux becomes the key material, which directly affects the mechanical properties (especially plasticity and low temperature toughness), crack resistance, occurrence rate of welding defects and welding productivity of the weld metal. The weight ratio of welding wire to flux is wire: flux = 1.1-1.6, depending on the type of welding joint, the type of flux used and the welding specification parameters. Compared with smelting flux, the amount of sintered flux is less, about 20% less. 單絲埋弧焊在焊管焊接時由於焊接熔池體積小、質量小（xiǎo）、存在時間短（duǎn）、結晶冷（lěng）卻速度快，在一定的焊接規範下，焊速受到限（xiàn）製，一般為300~600mm/min,過快的焊速極易（yì）導致熔池冷卻結晶速（sù）度快而產生焊接缺陷，過慢的速度又（yòu）導致熱輸入過大、熱影響區增寬而使接頭性能下降、生產效率低。而多絲埋弧焊大都是多絲縱向串（chuàn）列，在（zài）焊接過程中形成一個共用熔池，三絲（sī）焊時熔池長度即可達（dá）到80~100mm以上，熔池（chí）存在時間長、冶金反應充分，有充裕的時間供氣（qì）體和雜質浮出。焊接質量（liàng）好，隻要工（gōng）藝和規（guī）範控製的好，焊接缺陷很少。焊速可達到1.0~2m/min以上,生產效率高（gāo）。比單絲埋弧焊高3~5倍。
Single wire submerged arc welding (SSAW) for welded pipes is characterized by small weld pool volume, small quality, short existence time and fast crystallization cooling speed. Under certain welding specifications, the welding speed is limited. Generally, the welding speed is 300-600 mm/min. Over-fast welding speed can easily lead to rapid crystallization rate of weld pool cooling and welding defects. Over-slow welding speed also leads to excessive heat input and widening of heat affected zone, which results in joint performance. Decreased production efficiency. The multi-wire submerged arc welding is mostly multi-wire longitudinal series, forming a common molten pool in the welding process. The length of the molten pool can reach more than 80-100 mm during three-wire welding. The molten pool exists for a long time, the metallurgical reaction is sufficient, and there is sufficient time for gas and impurities to float out. Welding quality is good, as long as the process and specifications are well controlled, there are few welding defects. The welding speed can reach more than 1.0~2 m/min, and the production efficiency is high. It is 3 to 5 times higher than single wire submerged arc welding.
埋弧（hú）焊(含埋弧堆焊及電渣堆焊等)是一種電弧在焊劑層下燃燒進（jìn）行焊接的方法。其固有的焊接質量穩定、焊接生產率高、無弧光及煙塵很（hěn）少等優點，使其成為壓力容器（qì）、管段製造、箱型梁柱等重要鋼結構製作中的主要焊接方法。近年來，雖然先後出現了許多種高效、優質的新焊接（jiē）方法，但埋弧焊的（de）應用領域依然未受任何影響。
Submerged arc welding (including submerged arc surfacing and electroslag surfacing) is a method of arc combustion under flux layer for welding. Because of its inherent advantages of stable welding quality, high welding productivity, no arc and little smoke, it has become the main welding method in the manufacture of important steel structures such as pressure vessels, pipe sections and box-shaped beams and columns. In recent years, although there have been many new welding methods with high efficiency and quality, the application field of SAW has not been affected.
焊管的多絲埋弧（hú）焊是指使用兩根（gēn）或兩根以上焊絲完成同一焊縫的埋（mái）弧焊。焊管的多（duō）絲埋弧（hú）焊機組焊接裝置：內焊裝置由機械係統、電氣控製係統（tǒng）、焊接係統、焊（hàn）劑供給及回收係統、攝像監視係統五部（bù）分組成。其中機械係統主要包（bāo）括：焊接機頭、懸臂梁、懸臂梁支撐機構、焊縫跟蹤調節係統、機座及地線升降（jiàng）架等。
Multi-wire submerged arc welding of welded pipe refers to submerged arc welding of the same weld with two or more welding wires. Welding device of multi-wire submerged arc welding machine for welded pipe: The internal welding device consists of five parts: mechanical system, electrical control system, welding system, flux supply and recovery system, video surveillance system. The mechanical system mainly includes: welding head, cantilever beam, cantilever beam support mechanism, seam tracking adjustment system, machine base and wire lifting frame, etc.
焊絲的傾斜方向分為前傾和後傾。傾角的方向和大小不同，電（diàn）弧對（duì）熔池（chí）的力和熱作（zuò）用也不同，從而（ér）影響焊縫成形。當焊絲後傾一定角度時，由於電弧指向焊接方（fāng）向，使熔池前麵的焊件受到了預熱作用，電弧（hú）對熔池的液態金屬排出作用減弱，而導致焊縫寬而熔深變淺。反之，焊縫寬度較小（xiǎo）而熔深較大，但易使焊縫（féng）邊緣產生未熔合和咬邊，並且使焊縫成形變差（chà）。
The inclination direction of welding wire can be divided into forward inclination and backward inclination. The direction and size of inclination angle are different, and the force and heat effect of arc on molten pool are also different, thus affecting the weld formation. When the welding wire is inclined backward at a certain angle, the welding parts in front of the molten pool are preheated because the arc points to the welding direction, and the discharge of liquid metal from the molten pool is weakened by the arc, which results in the weld width and shallow penetration. On the contrary, the weld width is smaller and the penetration is larger, but it is easy to cause the weld edge to produce unfused and undercut edges, and make the weld formation worse.
