在焊管焊接過程中，埋弧（hú）焊也是利用（yòng）電弧作為熱源（yuán）的焊接（jiē）方法。埋弧焊時電弧是在一層顆粒狀的可熔化焊（hàn）劑覆（fù）蓋...埋弧焊電源一般應具有陡降外特性，可用交流(弧（hú）焊（hàn）變壓器)、直流(弧焊發電機或（huò）弧焊整流器)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（wéi）關鍵材料，它直接影響焊縫金屬的力學性能(特別（bié）是塑性及低溫韌性)、抗裂性能、焊（hàn）接缺陷發（fā）生率及焊接生產率等。焊絲與焊劑的配用重量（liàng）比為焊絲：焊劑=1.1～1.6，視焊接接頭類型、所用焊劑種類、焊接規範參數而定。與熔煉焊劑相比，燒結焊劑用（yòng）量較為（wéi）節省，約（yuē）可少用20%左右。
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（dān）絲埋弧焊在焊管焊接時由於焊接熔池（chí）體積小、質量小、存在時間短、結晶冷卻（què）速度快，在一定的（de）焊接規範下，焊速受到限製，一般為300~600mm/min,過快的焊速極易導致熔（róng）池（chí）冷卻結晶速度快而產生焊接缺陷，過慢的速度又導致熱輸入過大、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（zòng）向串（chuàn）列（liè），在焊接過程中形成一個共（gòng）用熔池，三絲（sī）焊時熔池長度即可達到80~100mm以上，熔池存在時間長、冶金反應充分，有充裕（yù）的時間供（gòng）氣體和雜質浮出。焊接（jiē）質量好，隻要工藝和規範控（kòng）製的好，焊接缺陷很少。焊速可（kě）達到1.0~2m/min以上,生產效率高。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.
埋弧焊(含埋弧堆焊及電渣堆焊等)是（shì）一種電弧在焊（hàn）劑層下燃燒進行焊接的方法。其固有的焊接質量穩定（dìng）、焊接生產率高、無弧光及煙（yān）塵（chén）很少等優點，使其成為壓力容器、管段製（zhì）造、箱型梁柱等重要鋼結構（gòu）製作中的主要焊接方法（fǎ）。近年來，雖然先後出現了許多種高效、優質的新焊接方法，但埋弧焊的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.
焊管的多絲埋弧焊（hàn）是指使（shǐ）用兩根或兩根（gēn）以上焊絲完成（chéng）同一焊縫的（de）埋弧焊。焊管的多（duō）絲埋弧焊機組焊接裝置：內（nèi）焊（hàn）裝置（zhì）由機械係統、電氣控製係統、焊接係統、焊劑供給及（jí）回收係統、攝像監（jiān）視係統五部分組成。其中機械係統主要包括：焊接機頭、懸臂（bì）梁、懸臂梁支撐機（jī）構、焊縫跟蹤調節（jiē）係統、機座及地線升降架等。
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（hòu）傾。傾角（jiǎo）的方向和大小不（bú）同，電弧對熔池的力和熱作用（yòng）也不同（tóng），從而影響焊縫成形（xíng）。當焊絲（sī）後（hòu）傾一定角度時，由於電弧指向（xiàng）焊接方向，使熔池前麵的焊件受到（dào）了預熱作（zuò）用，電（diàn）弧對熔池（chí）的液態金屬排出作用減弱（ruò），而導致焊（hàn）縫寬而熔深變淺。反之，焊縫寬度較小而熔深較大（dà），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。
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.
