Relationship between manual arc welding and manual argon shielded welding 5

1. Manual arc welding is electrode welding, and the molten pool is protected with a medicated coating; Argon shielded welding with argon to protect the molten pool, with welding wire.

2. Manual arc welding uses a variety of methods to protect the welding weld pool and prevent contact with the atmosphere. The heat energy is provided by the electric arc. As with MIG welding, the electrode is self-consuming.

The metal electrode is coated with a mineral flux, and when the flux melts, a welding slag (coating) is formed to cover the welding pool. The coated flux releases a gas-shielded weld pool containing alloying elements to compensate for alloy losses in the alloy pool.

3. Gas arc welding is an arc welding that uses gas as the arc medium and protects the arc and the welding area, which is called gas arc welding, referred to as gas arc welding.

Manual arc welding is the foundation, and when you generally learn, you must first learn manual arc welding, and then learn argon arc welding.

The welding materials of the two are different, arc welding uses welding rods, and argon arc welding uses welding wires.

Electrode arc welding uses coating melting to protect the molten pool and prevent oxygen and nitrogen in the air from entering the molten pool; TIG welding uses argon as a protective atmosphere.

Relatively speaking, argon arc welding is generally used to make thin plates, which are more seriously affected by the wind, while arc welding is more spicy, and large currents can weld thick plates, and then it is less affected by wind.

Manual arc welding is electrode welding, with coating to protect the molten pool, the electrode is divided into acidic and salty, and argon is used for argon shielded welding.

First, the welding method is different.

1. Manual arc welding: the method of using the manually operated electrode and the welded workpiece as two electrodes, and using the arc heat between the electrode and the weldment to melt the metal for welding.

2. Gas shielded welding: carbon dioxide or argon protection welding method, without welding rod and welding wire.

Second, the welding principle is different.

1. Manual arc welding: manual arc welding consists of welding power supply, welding cable, welding tongs, welding rods, welding parts, and arc to form a loop, and the welding rod and workpiece contact are used to ignite the arc during welding, and then the welding rod is lifted and kept at a certain distance, and the arc is stably burned under the welding power supply to provide a suitable arc voltage and welding current, resulting in high temperature, and the welding rod and welding parts are locally heated to a melting state.

2. Gas shielded welding: on the basis of the principle of ordinary arc welding, the protection of argon on the metal welding consumables is used, and the welding consumables are melted into a liquid state on the welded substrate to form a molten pool through high current, so that the welded metal and the welding consumables can achieve metallurgical combination.

3. Welding items are different.

1. Manual arc welding: the equipment is simple. Flexible and convenient operation. It can be welded in all positions and is suitable for welding a wide range of materials.

2. Gas shielded welding: mainly welding aluminum, titanium, stainless steel and other materials. Submerged arc welding is welding with welding wire and flux protection. The flux buries the arc like sand. It is mainly used for welding thick plates.

1. Hand arc welding: the method of using welding tongs to clamp the welding rod for welding; Manual arc welding, referred to as hand arc welding.

2. Gas shielded welding: arc welding method using metal welding wire as melting electrode and inert gas (CO2) as protection. Abbreviated as MAG.

3. Argon arc welding: a welding method that uses industrial tungsten or active tungsten as non-melting electric grade and inert gas argon as shielding gas. Abbreviated as TIG.

1. Hand arc welding uses the stable burning arc established between the electrode and the work to melt the electrode and the workpiece, so as to obtain a firm welded joint.

2. Gas shielded welding is a high-efficiency welding method, which uses CO2 gas as shielding gas and relies on the arc between the welding wire and the weldment to melt the metal. This welding method adopts automatic wire feeding, which has a large amount of applied metal, high production efficiency and stable quality.

3. Tungsten argon arc welding is a method that uses argon as the shielding gas and tungsten electrode as the non-melting electrode, with the help of the arc generated between the tungsten electrode and the weldment, heats and melts the base metal (and the welding wire is also melted at the same time). Argon is used to protect the weld metal and tungsten electrode melt pool from oxidation by air in the arc heating area.

1.Carbon dioxide gas arc welding (CO2 welding for short) is a method of welding with carbon dioxide gas as the shielding gas (sometimes using a mixture of CO2+AR).

It is easy to operate in terms of application and is suitable for automatic welding and all-round welding. Poor wind resistance during welding, suitable for indoor operations.

Due to its low cost, carbon oxide gas is easy to produce and is widely used in enterprises of all sizes.

Due to the special influence of the zero thermophysical properties of carbon dioxide gas, when using a conventional welding power supply, it is impossible for the molten metal at the end of the welding wire to form a balanced axial free transition, and it is usually necessary to use a short circuit and a molten droplet necking explosion, so there is more spatter than the free transition of MIG welding.

However, if a high-quality welding machine is used, the parameters are selected appropriately, and a very stable welding process can be obtained, so that the spatter can be reduced to a minimum. Due to the low cost of shielding gas** used, the weld seam is well formed with short transitions, and the use of welding wire containing oxygen absorber results in high-quality welded joints with no internal defects. Therefore, this welding method has become one of the most important welding methods for ferrous materials.

2.Manual soldering is a basic operation skill in the assembly of electronic products, which is suitable for product trial production, small batch production of electronic products, debugging and maintenance of electronic products, and some occasions that are not suitable for automatic welding.

It is a soldering process that uses a soldering iron to heat the soldered metal parts and tin-lead solder, and the molten solder wets the heated metal surface to form an alloy, and connects the soldered metal parts after the solder solidifies, so it is also called soldering.

3.A type of extremely inert gas shielded welding (TIG).

It is a welding method that uses arc heat to melt the base metal and filler wire under the protection of argon to form a joint missing joint.

It mainly controls three parameters: welding current, welding speed and argon flow. Compared with manual welding, the arc and weld pool are visible and easy to operate; Sheet metal structures that can be welded to active metals; Weld seam***, the joint strength can reach 80% 90% of the base metal. In 1930, inert gas shielded welding was invented in the United States, and in 1957, China began to use tungsten argon arc welding.

It can weld stainless steel, high-temperature alloy, titanium alloy, aluminum alloy and other materials, and is used in nuclear energy, aerospace, shipbuilding, electronics, metallurgy and other industries.

Manual arc welding: an arc welding that relies on manual manipulation of bucket height electrodes for welding, which is the most commonly used method in engineering welding. In manual arc welding, the arc heat generated between the coated electrode and the workpiece is used to melt the electrode and the workpiece, form a molten pool and carry out a series of complex physical metallurgical reactions, and form a weld after cooling to connect the workpiece into a whole.

The equipment used in manual arc welding is simple, the method is simple and flexible, and it is suitable for welding in any space position, but the operation technology requirements for welders are high, the labor intensity is high, the labor conditions are poor, and the production efficiency is low. The guarantee of welding quality depends to a large extent on the technical level of the welder.

Manual arc welding is suitable for the welding of carbon steel, low alloy steel, stainless steel, copper and copper alloy, aluminum and aluminum alloy and other metal materials, as well as cast iron welding and surfacing welding of various metal materials.

For active and refractory metal materials such as titanium, niobium, zirconium, molybdenum and other materials, manual arc welding is generally not used due to the unsatisfactory protection effect and the quality does not meet the requirements; For low melting point metal materials such as lead, tin, zinc, etc., due to the high arc temperature, manual arc welding is not used.

Gas welding: A welding method that relies on the flame energy generated by the violent combustion reaction of gas and oxygen to heat and melt the base metal. Commonly used gases include acetylene, liquefied petroleum gas and hydrogen.

Gas welding does not require a power supply, making it especially suitable for field construction in areas where there is no power supply. However, the temperature of the gas welding flame is low, and the heat is relatively dispersed; low production efficiency; large welding deformation; Poor joint performance. Gas welding is often used for the welding of thin plates and small-diameter pipes that are not very demanding.

The gas welding flame is a heat source for thermal cutting, and can also be used as a heat source for on-site copper tube brazing; The lead lining of the equipment is also commonly used for hydrogen-oxygen flame welding.

Welding examples of manual arc welding: steel structure, steel grid, steel truss steel structure layers: super high-rise steel structure construction parts: main body, steel columns, steel beams, steel support steel structure adopts manual arc welding.

The direction of the welding bar of gas shielded welding must be a regular swing bar from the left arc to the right, and the welding is a far swing from the bottom to the top. The far direction of protection welding is also from left to right welding, and it can also be drawn from right to left, and in the case of joint welding, it is drawn from top to bottom without swinging.

In manual arc welding, the technique is oriented to vertical welding, so due to the gravity of the molten iron, the molten metal will flow down, and the arc blowing force will increase the penetration depth, and the weld bead will be narrow and high.

Protective welding is different according to the direction of movement of the welding wire, there are right welding method and left welding method. When welding in the right direction, the molten pool can be well protected, and the heating is concentrated, the heat can be fully utilized, and the molten pool metal can be pushed to the rear due to the blowing force of the arc. In this way, the weld bead with a relatively full shape can be obtained, but the right-facing welding method is not easy to accurately grasp the welding direction, and it is easy to weld off, especially in the butt welding.

When the left direction is welded, the arc has a preheating effect on the weldment metal, which can obtain a large penetration depth and improve the shape of the weld. Although it is difficult to observe the molten pool, it can clearly grasp the welding direction and is not easy to weld off, and the semi-automatic CO2 welding method with a forward angle is used, and the forward angle is 10-15°.

There are two ways of vertical welding for protection welding, one is bottom-up vertical welding; The other is vertical welding from top to afternoon. Hand arc welding requires a special electrode to ensure the formation of the weld bead because of the downward vertical welding, so it is usually only used upward vertical welding, and if the first excitation CO2 protection welding adopts filament short circuit transition (i.e., short arc) welding, the downward vertical welding can be taken to obtain good results.

Ordinary arc welding must be pulled from left to right, which is not right, there is no such thing as necessary, you can also pull from right to left, as long as the angle of the welding rod is adjusted. It's just that it's easier to use from left to right.

The technique is oriented to vertical welding, then due to the residual force of the molten iron, the molten pool metal residual destruction and cultivation flow, coupled with the arc blowing force, the penetration depth increases, and the weld bead is narrow and high.

Manual arc welding is a method of using the heat of the arc between the electrode and the weldment to melt the metal by using the heat of the arc between the electrode and the weldment as two electrodes. Carbon dioxide gas shielded welding is a gas liquid-holding punching welding method that uses carbon dioxide gas as the shielding gas and relies on the electric arc generated between the welding wire and the weldment to melt the metal.

If it is a pressure vessel, it cannot be shielded by carbon dioxide gas shielded welding, and can only use manual arc welding, submerged arc automatic welding and argon arc welding. The longitudinal seam of the welding cylinder and the large-diameter annular seam should be automatically welded with submerged arc, and manual arc welding can be used if it is not convenient for automatic submerged arc welding. The upper tube is planted with manual arc welding; For the welding bead of single-sided welding and double-sided forming, it is advisable to use argon arc welding as the base, manual arc welding cover or submerged arc automatic welding mask.

Advantages: 1. The equipment is simple, cheap and easy to maintain. There is no need for complex auxiliary equipment during welding operation, only simple auxiliary tools need to be equipped, which is easy to carry.

2. There is no need for auxiliary gas protection, and it has strong wind resistance.

3. Flexible operation, strong adaptability, where the electrode can reach the place can be welded. Electrode arc welding is suitable for welding single or small batches of workpieces, as well as irregular, arbitrary spatial positions and welds that are not easy to achieve mechanized welding.

4. It has a wide range of applications, and can weld most of the metals and alloys in industrial applications, such as carbon steel, low-alloy structural steel, stainless steel, heat-resistant steel, low-temperature steel, cast iron, copper alloy, nickel alloy, etc. In addition, electrode arc welding can also be used for welding of dissimilar metals, repair welding of cast iron, and surfacing welding of various metal materials.

Disadvantages: 1. The labor intensity of welders is high and the working conditions are poor. When welding, the welder always carries out manual operation and eye observation in the environment of high temperature baking and toxic smoke.

2. Low production efficiency. Compared to automated welding methods, electrode arc welding uses less welding current and requires frequent replacement of the electrode.