Welding
The American Welding Society defines welding as “a localized coalescence of metals wherein coalescence is produced by heating to suitable temperatures with or without the application of pressure and with or without the use of the filler metal. The filler metal either has a melting point approximately the same as the base metals or has a melting point below that of the base metals but above 800 ℉.” There are 34 different welding processes.
Gas Welding
Gas welding is “a group of welding processes wherein coalescence is produced by heating with a gas flame or flames with or without the application of pressure and with or without the use of the filler material.”
There are 3 different gas welding processes:oxyacetylene welding(OAW), oxhydrogen welding(OHW),pressure gas welding(PGW).Of the 3 types of gas welding, oxyacetylene welding(OAW) is the one most frequently employed.This method uses a mixture of oxygen and acetylene to produce heating.Fluxes may be used to reduce oxidation and to promote a better welding point.This type of welding is suitable for both ferrous (including cast iron) and nonferrous metals and is capable of welding thick metals sections.
Oxyhydrogen welding(OHW) is used for low melting point metals such as aluminum,magnesium and lead.
Pressure gas welding(PGW) uses an oxyacetylene flame for a heat source but does not require a filler rod.Instead,fusion is obtained by applying pressure to the heated parts,either while being heated or after the parts are heated.This form of welding can be used for jointing both ferrous and nonferrous metals.
Arc Welding
Arc welding is “a welding processes wherein coalescence is produced by heating with an arc or arcs with or without the application of pressure and with or without the use of filler metals.”There are eight different arc welding processes:(1) carbon-arc welding,(2) shielded metal-arc welding,(3) flux cored arc welding,(4) gas metal-arc welding,(5) gas tungsten-arc welding,(6) submerged arc welding,(7) plasma-arc welding,and (8)stud welding.
The most widely used of these methods is the shielded metal-arc welding(SMAW) process. It is defined as an arc welding process wherein coalescence is produced by heating with an arc between a covered metal electrode and the work.Shielding is obtained from decomposition of the electrode covering.Pressure is not used and filler metal is obtained from the electrode.
The shielded metal-arc process is employed in both manual and automated production setups.Electrodes are available that permit the welding of ferrous metals (including cast iron) ,all grades of carbon steels ,low-alloy high-strength steels,stainless steels,copper bearing steels, copper alloys,aluminum,nickel,nickel alloys, and bronze.This welding technique is used in many fields,particularly in the manufacture of machinery,transportation equipment,piping systems and in various strctures (for example,buildings,trusses,machine bases,and so on ).
The next two most widely used arc welding methods are the submerged arc welding(SAW) process and the plasma-arc welding (PAW) process.
Submerged arc welding (SAW) is “an arc welding process wherein coalescence is produced by heating with an arc or arcs between a bare metal electrodes and the work.The arc is shielded by a blanket of granular fuseable material on the work.Pressure is not used and filler metal is obtaind from the electrode and sometimes from a supplyementay welding rod. ”
This method can be used in fully automated equipment where the feeds of both the electrode and granular flux are controlled.The method is also adaptable for semiautomatic equipment where the feeds of the electrode and granular flux are contolled manually .Since the granular flux must cover the joint to be welded, this method is restricted to parts in horizontal position and is particularly suited for welding long straight joints .Also,fewer passes are needed to weld thick metal sections than are usually required by shielded metal-arc welding.
Submerged arc welding can be used to weld low carbon steels,high-strength low-alloy steels,chromium steels and austenitic chromium-nickle steels.With special methods, it is also possible to weld high-alloy air-hardening steels.
Plasma-arc welding (PAW) is “an arc welding process wherein coalescence is produced by heating with a constricted arc between an electrode and the workpiece ( transferred arc ) or the electrode and the constricting nozzle ( nontransferred arc ) Shielding is obtained from the hot,ionized gas issuing from the orifice ,which may be supplemented by an auxiliary source of shielding gas.shielding gas may be an inert gas or a mixture of gases. Pressure may or may not be used ,and filler may or may not be used,and filler may or may not be supplied .”
Plasma-arc welding is used for quality welding and can easily weld 5-in. thick aluminum sections or stainless sections up to 4-in.thick.Since there are no products of combustion,the welded joints have no porosity and display a strong resistance to high stresses and impact loading.
The plasma torch is constructed with an electrode centrally within a metal cup that guides an inert streaming gas past the electrode.In the plasma-arc torch the discharge end of the cup is smaller in diameter than the upper diameter so that a discharge noozle is created.In addition ,the inner wall of the nozzle is lined with a ceramic material .
Although a plasma stream can be created with any gas ,a gas that is nonoxidizing should be used .Another important requirement is thermal conductivity of the gas rather than the temperature it attains .Thus ,gases of the conductivity can transfer more heat ,making it possible to weld bulky sections more easily .Argon ,helium,and hydrogen,are the gases mostly frequently used. Hydrogen has the higher thermal conductivity and produces hotter arcs than those produced by argon or helium.
Other forms of arc welding,namely, carbon-arc ,flux cored arc ,gas metal –arc,gas tungsten-arc ,and stud welding ,are used for joining particular metals or for mass production. For example ,whereas flux cored arc welding uses a flux cored electrode,continuously fed from a spool for quantity production.
Stud welding is accomplished by means of a stud-welding gun,which welds a stud to the surface of a workpiece.The method is extensively employed in the automotive,shipbuildng,railroad,and building construction industries.
Resistance Welding
Resistance welding is “a group of welding processes wherein coalescence is produced by the heat obtained from resistance of the work to electric current in a circuit of which the work in a part ,and by the application of pressure.”There are six types of resistance welding processes.these are (1)resistance spot welding,(2)resistance seam welding,(3)projection welding,(4)flash welding,(5)upset welding, and (6)percussion welding.Resistance welding is widely used for quantity production.By means of proper controls and tooling,it is readily adaptable to automation,including any required welding are the spot,seam,and projection forms of welding.
Resistance Spot Welding (RSW).”A resistance welding process wherein coalescene at the faying surfaces is produced in the heat obtained from the resistance to electric current through the work parts held together under pressure by electrodes.The size and shape of the individually formed welds are limited primarily by the size and contour of the electrodes.”
Spot welding is primarily restricted to thin metals (for example,0.001 in thick to 0.125 in.thick for steel and magnesium,0.16 in. thick for aluminum ) ,namely,steels,stainless steels,aluminum,nixkel,nickel alloys,bronze ,and brass.Some dissimilar metals can be spot welded,but with difficulty.
Resistance Seam Welding (RSW) “A resistance welding process wherein coalescene at the faying surfaces is produced in the heat obtained from the resistance to electric current through the work parts held together under pressure by electrodes. The resulting weld is a series of overlapping resistance-spot welds made progressively along a joint by rotating the electrodes.” In principle, seam welding is similar to spot welding except that the weld is continuous by virtue of the rollers rather than discontinuous as in spot welding.
Seam welding is primarily used for quantity production but is restricted to joining metal gages that are thinner than those which can be joined by spot welding .The normal range of thicknesses compatible with seam welding is 0.100-0.125 in.
Projection Welding (RPW) “A resistance welding process wherein coalescene at the faying surfaces is produced in the heat obtained from the resistance to electric current through the work parts held together under pressure by electrodes. The resulting welds are localized at predetermined points by projections ,embossment,and intersections.”
Projection welding is a process similar to spot welding except that the projections tend to localize the heat ,permitting thicker materials to be welded.Simultaneous welds are readily made by this method ,and result in a stronger welded struture than that obtained with spot welding.
Flash Welding (FW).In this process abutting surfaces to be welded are clamped in futures and brought within close proximity ( or light contact ) of each other so that an electric arc is surfaces are forced together, completing the weld .Forcing the two surfaces together causes the metal to be displaced ( that is ,bulge) outward from the welded joint. This upset metal is usually removed after welding. Preheating ( for large bulky parts ) and postheating ( that is heat treatment ) can readily be made part of the overall welding cycle.
Materials that are easily welded by spot welding are also weldable by flash welding ,although the method is used mostly with ferrous metals. Copper, copper alloys and some aluminums can not be relied upon to produce satisfactorily welded joints. However, dissimilar metals can readily be welded by this methods, including even refractory metals such as tungsten , molybdenum ,and tantalum.
Upset Welding (UW).A process similar to flash welding except the parts to be welded are held in close contact with each other before the electric circuit is cloded .Thus ,there is no flashing in this method. Upset welding is extensively used in the fabrication of tubular sections ,pipe,and heavy steel rings ;it is also used for joining small ferrous and nonferrous strips.
Percussion Welding (PW). “A resistance welding process wherein coalescence is produced simultaneously over the entire abutting surfaces by heat obtained from an arc produced by a repaid discharge of electrical energe with pressure percussively applied during or immediately following the electrical discharge.”
Percussion welding is used for special joining situations ( for example ,joining dissimalar metals that can not be welded economically by flash welding ).This welding method is also used to weld pins ,studs,bolts,and so on,to other components as well as to join sections of pipe,rod ,or tube to each other or to flat sections.
Brazing
Brazing is “a group of welding processes wherein coalescence is produced by the heat and by using a filler metal having a liquidus above 800 ℉ and below the solidus of the base metals .The filler metal is distributed between the closely fitted surfaces of the joint by capillary attraction”.There are six brazing welding methods .Those are (1)infrared brazing,(2)torch brazing,(3)furnace brazing ,(4)induction brazing,(5)resistance brazing ,(6)dip brazing. Among these methods ,the primary difference is the manner in which the metal to be joint are heated .Also ,only four of the six methods are of industrial importance ,torch brazing, furnace brazing,induction brazing,and dip brazing. These methods are defined and briefly described in the following paragraphs.
Torch Brazing. (TB)
A joint process that may employ acetylene ,natural gas ,butane,or propane in combination with air or oxygen to supply the heat required to melt the filler rod and diffuse it into the surface of the base metal.This technique is not extensively used for continuous mass production .
Furnace Brazing .(FB)
A high production fabrication method where the heat is supplied by gas or electric heating coils. The furnace of the box type or the continuous type ,which employ a wire mesh belt to transport the part to be brazed. Furnace brazing requires that preformed shapes of filler metal be placed on the parts to be jointed prior to entering the furnace .This method of brazing is well suited to high production and can avoid the use of fluxing by maintaining an insert atmosphere in the furnace.
Induction Brazing .Like furnace brazing ,induction brazing requires the use of preformed shapes of filler metal .Heat is produced by placing the parts to be brazed within the field of a high frequency induction coil, the heat can be applied in the local area of the joint to be brazed.Induction brazing can be used for mechanized production when properly designed tooling and feeding devices are incorporated into the production setup.
Dip Brazing .(DB)
Parts can be dip brazed by one of two methods. In chemical dip brazing,the parts to be jointed are prepared with preformed filler metal,after which they are placed into a molten bath brazing flux .In the molten metal bath process,the assembled parts are first refluxed and then immersed into a molten bath of filler metal. This latter method of brazing is restricted to small parts,whereas the former method is more adaptable for joining large parts.
Other Welding Processes
The master chart of welding processes shows,in addition to the aforementioned methods,a series of solid state welding techniques and some other processes. These methods are defined by the American Welding Society as following:
Ultrasonic Welding (UW)
A solid state welding process wherein coalescence is produced by the local application of high frequency vibratory energy as the work parts are held together under pressure .
Friction Welding.(FW)
A solid state welding process wherein coalescence is produced by the heat obtained from mechanically induced sliding motion between rubbing surfaces.The parts are held together under pressure.”
Forge Welding .(FW)
A solid state welding process wherein coalescence is produced by heating and by applying the pressure or blows sufficient to cause permanent deformation at the interface .”
Explosion Welding .( EW )
A solid state welding process wherein coalescence is produced by high velocity movements produced by a controlled detonation.
Diffusion Welding .
A solid state welding process wherein coalescence of the faying surfaces is produced by the application of pressure and elevated temperatures.The process does not involve macroscopic deformation or relative motion of parts .A solid filler metal may be or may not be inserted .”
Cold Welding (CW)
“A solid state welding process wherein coalescence is produced by the external application of mechanical force alone .”
Thermit Welding (TW)
“A group of welding processes wherein coalescence is produced by heating with superheated liquid metal and slag resulting from a chemical reaction between a metal oxide and aluminum with or without the application of pressure .Filler metal ,when used,is obtained from the liquid metal.”
Laser Beam Welding (LBW)
“A welding process wherein coalescence is produced by the heat obtained from the application of a concentrated coherent light beam impinging upon the surfaces to be joined.”
Induction Welding ( IW )
“A welding process wherein coalescence is produced by the heat obtained from the resistance of the work to induced electric current with or without the application of pressure.”
Electroslag Welding (EW)
“A welding process wherein coalescence is produced by molten slag which melts the filler metal and the surfaces of the work to be welded. The weld pool is shielded by this slag which moves along the full cross section of the joint as welding progresses . The conductive slag is maintained molten by its resistance to electric current passing between the electrode and the work. ”
Electron Beam Welding (EBW) .
A welding process wherein coalescence is produced by the heat obtained from a concentrated beam composed primarily of high velocity electrons impinging upon the surfaces to be joined.
焊接
美国焊接协会将焊接定义为：“金属的局部结合”。在这部分金属中，结合区是由加热到适当温度而得到的，而这种适当温度的获得，可以通过使用压力或不使用压力，使用填料金属或不使用填料金属。使用的填料金属或者有与焊件相同或相近的熔点，或者熔点在其焊件以下，但必须在800℉以上。有34钟焊接方法，它们分别如下：
气焊
气焊是一组焊接工艺方法的组合。说到这种焊接方法，其焊区是通过用一束气体火焰或多束气体火焰加热，加压或者不加压，利用填料金属材料或不使用填料材料而获得的。
在所有气焊方法中，人们最常使用的是氧乙炔焊。这种方法是利用氧气和乙炔的混合气体来产生热量，利用焊剂可以降低焊区的氧化程度，从而获得一个更好的焊点。这种焊接方法适用于黑色金属（其中包括铸铁）和有色金属，同时也能够胜任比较厚的金属焊件。
氢氧焊适用于熔点比较低的金属。比如，铝·镁·和铅。
加压气焊利用氧乙炔火焰作为热源，但是，不需要填料金属。相反，焊接熔合区一般通过对被加热的构件施加压力获得，或者在被加热的过程中，或者在构件加热后，得到这种熔合区。这种焊接方法能够用于黑色金属和有色金属当中。
电弧焊
电弧焊是这样一种焊接工艺方法：焊接区通过一束电弧或多束电弧加热产生。在这过程中可以施加压力，也可以不施加压力；可以使用填料金属，或不使用填料金属获得。有八种不同的电弧焊方法。它们是：（1）碳弧焊，（2）保护金属电弧焊，（3）焊芯电弧焊，（4）气保护金属极电弧焊，（5）气保护钨极电弧焊，（6）埋弧焊，（7）等离子焊接，（8）电栓焊 。
在这些方法中，最常用的是保护金属电弧焊。
它被定义为这样一种焊接方法，在焊接过程中，焊接区是通过电弧焊产生的热量而融化形成的，而这种电弧是在工件和覆盖金属药皮的焊条中产生。这种保护来源于覆盖电极的分解，其中并未施加压力，填料金属也来源于电极。
在人工和自动化生产装备中，保护金属电弧焊这种工艺方法都会用到。电极也可以用于黑色金属（包括铸铁），所有不同型号的碳钢，轴承钢，铜合金钢，铝，镍，镍合金，和其他铜制品。这种焊接技术用于很多领域，尤其用在机械，交通设备，管道系统的生产和不同的结构中。例如，建筑，机座，构架等等。下面介绍的两种广泛使用的焊接方法是埋弧焊工艺方法和等离子焊工艺方法。
埋弧焊
它是这样一种电弧焊工艺方法：其中，焊接区通过加热产生，而这种加热是通过一束或多束电弧实现的，电弧又是由一个单金属极或多个金属极和工件之间产生的。这种电弧由位于工件上的粒状的可熔化地材料所保护，在这个过程中，可以不施加力，也可以施加力，而所需要的填料金属，可以从电极中获得。当然，有时可以从附加的材料中获得。
这种工艺方法能够用于所有自动化设备中。在这种设备中，电极和粒状焊剂的进给量是被控制的。这种方法同样也适用于半自动化生产装备中，在这些半自动化生产装备中，电极和粒状焊剂的进给量是有人工所控制的。既然，这种粒状焊剂必须覆盖焊接点，那么这种方法将被限制在只能用于水平位置的焊件，尤其适合那种比较长而又比较直的焊接点。同样，比起其他焊接方法，人类通常需要保护金属电弧焊去焊接那些比较厚的金属。
埋弧焊可用于那些低碳钢，高强度低合金钢，烙合金钢，烙镍合金钢。如果采用某些特别方法，那么也有可能焊接高合金钢。
等离子焊
它是这样一种焊接方法：其中焊接区已由加热产生，而所需要的热量是由一种压缩电弧供应，而这种压缩电弧是在一个电极和工件（传导电弧）产生的，或者是在一个电极和压缩喷嘴（非传导电弧）产生的。这种保护作用由一种热的电离气体实现的。这种气体是从金属环发射端发射出来，或者是由外加的辅助保护气所提供。而这种保护气或许是由一种插入式气体，或是一种气体混合物。外加压力可以用，也可以不用，而且填料也可以用也可以不用。
等离子焊用于要求焊接质量要求较高的焊接场所中，能够焊接5英尺厚的铝构件中，或无缝钢可以达到4英尺厚。既然没有燃烧的物体供热，那么焊接点便没有高强度，不能够承受高压和冲击载荷。
这种等离子电弧由处于一个金属环中的电极所引导，而这个金属环能够通过电极引导内部气流。在这些等离子束中金属环的发射末端在尺寸上比金属环的上端尺寸小。这样一个发射喷嘴便产生了较大气流，另外一个喷嘴内壁线性排列在一种陶瓷材料上。
虽然等离子束能够由多种气体产生，但必须保证这些气体不被氧化，否则不应该被使用。对这种要求较高的便是这种气体的比热容（热量传递率），而不是它所能获得的温度。因此，较高比热容的气体能够传递较多的热量，这种特性使该气体更使用于焊接，较大的构件也可以。氩气，氦气，氢气，也是比较常用的气体。相比氩气和氦气，氢气有比较高的比热容，能够产生温度较高的电弧。
其它形式的电弧焊，即是：碳弧焊，焊芯电弧焊，气保护金属极电弧焊，气保护钨极电弧焊和电栓焊。这些焊接方法常用在一些特定场合中，或者批量生产。例如，碳弧焊被用于镀锌的薄片钢，黄铜，青铜和铅。然而，尽管焊芯电弧焊使用一种焊芯电极，但在批量生产中仍持续的需要从卷轴焊料中获得。
电栓焊
它借助电栓焊枪来实现。电栓焊抢能够将一个电栓焊接到一个工件的表面。这种方法广泛用于汽车，造船，铁路及工厂基础设施机构建设。
电阻焊
它是一组焊接工艺方法的组合。在这种方法中，焊接区由加热形成，而这些热量来源于回路电阻。在电流回路中，工件作为电流回路的一部分，或者还要使用压力。共有六种电阻焊工艺。它们是：（1）电阻电焊，（2）电阻缝焊，（3）凸焊，（4）闪光焊，（5）电阻对焊，（6）储能焊。电阻焊应用于批量生产中，借助合理的工具及控制系统，他很方便的适用于自动化生产当中，其中也包括焊接后需要进行预热和进行热处理的任何工件中。在电阻焊中，使用最为广泛的是电阻点焊，电阻缝焊以及凸焊。
电阻点焊：
电阻点焊是这样一种焊接工艺方法，在接合面处的熔合区通过加热而产生，其中这些热量来源于通电电阻。通电回路是由在压力作用下，通过几个电极将工件连接在一起形成的。因此，所形成的焊接产品的形状和尺寸主要有电极的尺寸和轮廓形状所限制。电阻点焊仅仅局限于比较薄的金属焊接当中（例如，厚度在0.001英寸到0.125英寸的钢和镁，0.16英寸厚的铝片）即是，钢，铝，镁，镍，镍合金，青铜和黄铜。一些特性不相近的金属可以进行点焊，但是有困难。
电阻缝焊
他是这样一种电焊工艺方法：在这种方法中，结合区的焊接由加热产生，这种热量来源于通电电阻，这种通电回路是由在压力作用下，多个电极将工件连接起来的结果。最终的焊接有一系列的重叠的电阻焊接点所组成，而这些电阻焊接点是通过旋转各电极逐次沿着某一条焊缝而形成的。原则上，电阻点焊与电阻缝焊是相近的。
电阻缝焊主要用于焊接质量要球较高的焊件上，但这中焊接方法仅仅局限于焊接标准厚度的金属版，而这些金属板的厚度往往比那些用于点焊的金属板的厚度要薄的多。而电阻缝焊所能胜任的标准焊件厚度范围位于英寸0.100——0.125之间。
凸焊
它定义为这样一种焊接方法：在这种焊接方法中，结合面处的焊接区由加热产生，而这种热量来源于通电电阻，这种通电回路是由在压力作用下，多个电极将工件连接起来的结果。最终的焊接点位于预先决定的位置点上，而这些位置点往往由突出的隆起的部分以及相互接触的位置所决定。
凸焊是和点焊相似的一种焊接方法。其不同点在于，凸焊往往使提供的热量局部化，细化，从而使得这种方法能够焊接比较厚的金属材料。那么，由此以来，多处工件位置将可以进行同时焊接。这样，其最终结果便是在焊接结构的强度上，该种方法将比电阻点焊大。
闪光焊
在这种工艺方法中，两个对焊表面被固定地夹住，同时让它们相距很近。结果将在这两个对焊表面产生电弧，这样产生的电弧将促使它们加热到熔化温度。在这个焊件上，两个焊接表面通过外力结合在一起，完成了焊接。强加外力使得它们结合，这样会使焊接金属发生膨胀，将会向焊接点外部膨胀。在焊接完毕后，这部分多出来的金属往往被除掉。预热（对于大部分构件来说）和过后热处理（也就是热处理），完全可以作为整个焊接程序的一部分。
能够用于电阻点焊的材料，往往也能够用于闪光焊，虽然这种方法大部分用于黑色金属中，如铜，铜合金，还有一些铅制品。不能够使用这种方法获得令人满意的焊接点。但是，特性不相近的金属却可以使用这种工艺方法进行焊接，甚至包括一些难熔的金属，例如，钨，钼，以及钛。
电阻对焊
电阻对焊这种工艺方法和闪光焊很相似，除了有一点不同，那就是在电路切断之前，要焊接的工件彼此的紧密相接触，因此在这种方法中，便没有电弧光。电阻对焊广泛用于管状构件的连接，铜管，大型铜环。当然它也用于连接黑色和有色金属条。
储能焊（冲击焊）
储能焊是这样一种焊接工艺方法：在这种工艺方法，焊接熔合区是通过热量同时在整个对焊表面产生，而这种热量来源于一束电弧，而这种电弧是由伴随压力突然间施加，电能快速释放而产生的，这种力地施加，要么在电能释放期间，要么紧跟其后。
储能焊被用于特殊的焊接场合，（例如，焊接那些用闪光焊不经济的，特性不同的金属）。这种焊接方法也被用于焊接针状金属，电栓，螺栓等等，以及焊接其他的零部件。例如，管道，金属棒，或者细长管等它们之间的焊接或者它们与一些焊件的平面焊接。
钎焊
钎焊是这样一种焊接工艺方法：在这种工艺方法中，焊接熔合区通过加热到合适的温度，以及用一种填料金属而获得的，而这种填料金属拥有高于800℉的熔点，但是小于焊接件的凝固点。这种填料金属通过毛细作用被放置在两个距离很近的焊接件的表面。总共有六种钎焊焊接工艺方法，它们是：（1）红外线钎焊，（2）焊炬钎焊，（3）炉中钎焊，（4）感应钎焊，（5）电阻加热钎焊或者说接触钎焊，（6）浸渍钎焊。在这些钎焊方法中，最主要的不同点，便是要焊接的金属件其加热的方式。同时，六种方法中，也只有四种方法对工业具有一定的重要性，即是:炉中钎焊，感应加热钎焊，和浸渍钎焊。这些方法的定义及其简短的描述，在以下的段落中有所体现：
焊炬钎焊
这种焊接工艺方法可能会使用乙炔，天然气，丁烷，或者再结合空气，或者说氧气用以供应热量，这种热量用以熔化填料金属并将填充于焊接件的两表面，这种焊接技术并没有广泛的用于持续批量生产之中。
炉中钎焊
炉中钎焊是一种高生产率的焊接生产方法在这种方法中热量有燃烧的气体或者有电力加热的汽油所供应，这种炉具有盒子形状或持续的曲线形状。他是用一种线形网状带来传送要被钎焊的工件。在焊接件被送入炉中之前，炉中钎焊要求预先成型的填料金属，应该放置在被焊接的工件上。这种钎焊方法非常适用于大量生产中，他能够通过维持炉中的内部环境而避免焊剂的使用。
感应加热钎焊
正如炉中钎焊的那样，感应加热钎焊也要求使用成型的填料金属。热量是通过将需钎焊的零件放置在高频感应油当中，焊接的工件被涡流加热。因为焊接件提供电磁阻，用以改变其感应区，加热非常迅速，通过在感应油中的合理成型，那么产生的热量便能够用于钎焊的主要焊接区域。当设计合理的加工工具和进给装置安装在生产设备中，那么感应钎焊便能用于机械生产。
浸渍钎焊
工件可以通过两种方法中的一种进行钎焊。在化学浸渍钎焊中，要焊接的工件必须与预先成型的填料金属同时准备好，准备好之后，将它们放进一个装有钎焊剂的熔池里。在金属在熔池里进行溶化的这道工序里，组装的零件第一次被重新融化，然后进渍在装有填料金属的金属池里。钎焊的后一种方法主要用于焊接小的零件；然而，前一种方法便适用于焊接大的零件。
其他焊接工艺
除了前述的一些方法之外，还有一些固态的焊接技术和其他的焊接工艺方法。这些方法被美国工艺学会定义如下：
超声波焊
一种焊接区域处于固态时的焊接工艺方法，而这种熔合区的获得，是通过外加高频振动能量实现的，而工件是通过外加压力连接在一起。
摩擦焊
摩擦焊是一种固态焊接工艺方法，其熔合区的热量获得是从相互摩擦的两表面的机械感应的相对运动中实现的。这些工件的连接也是通过施加外力实现的。
锻焊
锻焊它是一种固态焊接方法，其熔合区的热量获得是通过加热或或使用压力或充分的锤击而在相互接触的两表面形成永久性的变形。
爆炸焊
爆炸焊它是一种固态焊接方法，其焊接熔合区受到高速运动的影响。
扩散焊
扩散焊它是一种固态焊接方法，其两接触表面熔合区的获得是通过压力的使用和逐步升高的温度。这种工艺方法并没有牵扯到宏观变形和工件的相对运动。固态填料金属可以使用也可以不使用。
冷焊
冷焊它是一种固态焊接方法，其两接触表面熔合区的获得是仅仅通过外加机械压力实现的。
热剂焊
热剂焊它是一系列的焊接工艺方法的组合，其两接触表面熔合区的获得是通过加热而实现的，热量来源于温度很高的液态金属，或者来源于一种化学反应的热量。这种化学反应是在一种金属氧化物和铝之间实现的。整个过程可以施加压力也可以不施加压力。当使用这种方法时填料金属是从液态金属中获得。
激光束焊
激光束焊是这样的一种焊接方法，其两接触表面熔合区的获得是通过加热而实现的，热量来源于固有激光束的使用，而这种激光束固在其金属表面。
电子束焊
电子束焊是这样的一种焊接方法，其两接触表面熔合区的获得是通过加热而实现的，热量来源于高速电子运动。
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