What kind of gas welding is used for the second welding machine? Is it OK with oxygen 5

Use carbon dioxide as a shielding gas for gas welding, oxygen will not work.

CO2 gas shielded welding.

According to the operation method, it can be divided into two types: automatic welding and semi-automatic welding. For long straight welds and regular curved welds, automatic welding can be used; For irregular or short welds, semi-automatic welding is used, and semi-automatic welding is the most widely used in production at present.

Carbon dioxide gas shielded welding can be divided into two types: fine wire welding and thick wire welding according to the diameter of the welding wire. Senda welding recommends that the diameter of filament welding is smaller, the process is more mature, and it is suitable for thin plate welding; The diameter used for thick wire welding is greater than or equal to, which is suitable for the welding of medium and heavy plates.

Second, the welding machine cannot use oxygen. It is better to use argon, but you can also use carbon dioxide with a mixture.

Second, shielded welding is the common name of "carbon dioxide gas shielded welding", and argon shielded welding (commonly known as "argon arc welding") and other gas shielded welding are called "gas shielded welding".

The advantages of the second protection welding are open arc welding, easy to achieve all-round semi-automatic and automatic welding, generally using bare welding wire, arc heat concentration, small heat-affected zone, welding deformation and small cracking tendency of welds, etc. Therefore, the welding operation is convenient, the weld quality is high, and the comprehensive cost is only half of that of manual arc welding and submerged arc welding.

However, due to the difficulty of pure carbon dioxide preparation, impurities such as water and nitrogen often cause large smoke and splash, so that the appearance of the weld is not smooth enough, and a dryer must be set in the gas path; Another disadvantage is that carbon dioxide is susceptible to high-temperature decomposition, generating carbon monoxide and oxygen, resulting in certain metal oxidation and porosity inclusions in the weld. (also one of the causes of melt pool splashing).

Second, the welding is mainly used for welding low-carbon steel and low-alloy steel structural parts with a thickness of less than 25mm, and is also commonly used for surfacing repair of wear parts and repair welding of iron castings.

I'm dizzy, you haven't even figured out the second welding machine. What is called two protection welding. The full name is called CO2 Protected Welder Machine.

It gets its name because carbon dioxide is used in welding. TIG welding is named because argon gas is used in welding. Of course.

Second, it is not necessary to use carbon dioxide for welding, it depends on what you weld. If welded stainless steel rigid wire. It is better to use argon.

It is also possible to use a mixture.

With carbon dioxide, not oxygen.

I've used oxygen, and when someone else goes to ventilate me, it's a puddle of mud.

How to wear the welding wire for the second protection welding.

With %80 carbon dioxide gas + %20 argon, called mixed gas, it is used for better welding effect, bright color, small spatter, and beautiful weld.

The full name of the second protection welding, carbon dioxide gas shielded welding, is a welding method.

This welding method has become one of the most important welding methods for ferrous materials.

Features: (1) Low welding cost. Its cost is only 40 50% of submerged arc welding and electrode arc welding.

2) High production efficiency. Its productivity is 1 4 times that of electrode arc welding.

3) Easy to operate. Open arc, no limit to the thickness of the workpiece, can be welded in all positions and can be welded downward.

4) High crack resistance of welds. The weld is low in hydrogen and also has less nitrogen.

5) The deformation after welding is small. The angular deformation is 5 thousandths, and the unevenness is only three thousandths.

6) Small welding spatter. Welding spatter can be reduced when ultra-low carbon alloy or flux-cored wires are used, or AR is added to CO2.

Related information. 1. The butt welds of important structures shall be inspected internally by a certain number of X-ray or ultrasonic joints according to the technical requirements of various design regulations, and shall be assessed according to the level specified in the design.

2. The surface weld is inspected, so all the structural welds are inspected, and the quality requirements of the weld appearance:

Weld straightness, any part within 100mm straightness 2mm.

The weld should transition smoothly and should not change the 90° transition angle.

The height difference of the weld is 25mm in length, and the height difference should be.

When the tolerance of the K value of fillet weld is 4mm of the thickness of the object; When the thickness of the object plate is 4mm. (k0 is the design leg size).

Weld undercut: when the plate thickness is 6mm d partial, d <.

When the thickness of the plate is 6mm d (d is the undercut depth).

The weld is not allowed to be lower than the surface of the workpiece, and cracks and defects that have not yet been fused exist.

The depth of concave at the intersection of the surface stacking of multiple welds should be 1mm.

All welding defects are allowed to be repaired, and they should be smoothed after repair.

When the component is made of steel casting, it must be annealed by 550 after welding to relieve stress.

Second, carbon dioxide gas is used for welding.

Argon is an inert gas that protects much better than carbon dioxide in welding.

Key points of operation: 1. The joint with the bevel in the vertical or inclined position must be welded from the bottom to the top, and the thin plate butt and vertical fillet welding without the groove can be welded downward; Flat, horizontal and vertical butt joints can be welded in the left direction.

2. When the wind speed is greater than 1m s in outdoor operations, windproof measures should be adopted.

3. A reasonable welding sequence must be selected according to the structure of the workpiece to be welded.

4. Arc striking and arc extinguishing plates of appropriate size should be set at both ends of the butt.

5. The dirt in the hose and the splash of the nozzle should be cleaned frequently.

Preparation for welding:

1. Before welding, the joint cleaning requires that the burrs, oil, rust, and oxide scale that affect the quality of the weld within 30mm on both sides of the groove must be cleaned.

2. When the construction environment temperature is lower than zero or the carbon equivalent of the steel is greater than that, and the structural rigidity is too large, and the object is thicker, preheating measures should be used before welding, the preheating temperature is 80 100, and the preheating range is 5 times the thickness of the plate, but not less than 100mm.

3. When the thickness of the workpiece is greater than 6mm, in order to ensure the welding penetration strength, the butt edge of the plate should be cut V-shaped or X-shaped, the groove angle is 60°, the blunt edge p is 0 1mm, and the assembly clearance B is 0 1mm; When the thickness of the plate is 4 mm, the butt edge of the thicker plate should be skewed.

Walk with argon.

Argon arc welding technology is based on the principle of ordinary arc welding, the use of argon to protect the metal welding consumables, through high current to make the welding consumables melt into a liquid state on the welded substrate to form a molten pool, so that the welded metal and the welding consumables to achieve metallurgical combination of a welding technology, because of the continuous delivery of argon in the high temperature melt welding, so that the welding consumables can not contact with the oxygen in the air, thereby preventing the oxidation of the welding consumables, so that stainless steel, iron hardware metals can be welded.

Advantages and disadvantagesArgon is an ideal shielding gas, which is 25% denser than air, which is conducive to the protection of the welding arc and reduces the consumption of shielding gas. Argon is a chemically inactive gas, which does not react with metals even at high temperatures, so there is no oxidation and burning loss of alloying elements and a series of problems caused by it.

Argon is also insoluble in liquid metals, so it does not cause pores. Argon is a monoatomic gas that exists in an atomic state with no molecular decomposition or atomic endothermic phenomena at high temperatures. The specific heat capacity and heat conduction capacity of argon are small, that is, the absorption capacity is small, the heat transfer to the outside is also less, and the heat in the arc is not easy to lose, so that the welding arc burns stably and the heat is concentrated, which is conducive to the welding.

The disadvantage of argon is that the ionization potential is higher. When the arc space is filled with argon, it is difficult to ignite the arc, but once the arc is ignited, it is very stable.

Carbon dioxide gas, not carbon dioxide.

2. Shielded welding: the abbreviation of carbon dioxide gas shielded arc welding. It is a kind of arc welding with carbon dioxide gas as the shielding gas.

The second guarantee welding replaces carbon dioxide gas with argon gas, which is not called the second guarantee welding. It's called: MIG welding (MIG welding). It is mainly used in the welding of aluminum and aluminum alloys.

Hello. Argon can be used for the second welding machine, argon is used for the second welding machine, stainless steel welding wire, and the welding effect is good for stainless steel.

Oxygen welding is a kind of active gas shielded welding, and the gas used is generally carbon dioxide gas or 28 mixed gas, and generally no inert gas is used. If you want to use argon, you must change to a MIG welding machine, and the effect of using an oxygen welding machine is not very good.

No. A welding machine that does not use carbon dioxide gas as a welding shielding gas is not called a second guarantee welding.

Second, welding gas is a by-product of the factory, which is wide and low. Its cost is only about 40% 50% of submerged arc welding and manual welding, under the same conditions, compared with hand arc welding, the former consumes about 40% 70% of the latter, the second welding can weld any position, the thin plate can be welded to 1mm, and the thickest is almost unlimited. Moreover, when welding thin plates, it is faster than argon welding speed and small deformation.

Second, precautions for the use of welding.

Effective windproof, rainproof and safety measures should be done before welding, and effective windproof measures such as wind shields must be used when the wind speed is greater than 2m s. If there is water around the seam or the seam is already wet, it is necessary to dry the seam before welding. In case of bad weather, stop welding.

Before construction, welders must bring necessary tools such as sharp hammers, wire brushes, flat shovels and wear labor protection supplies, nozzles must be cleaned up frequently splashes and other debris, and contact tips must be replaced if damaged. Avoid excessive bending of the torch hose during the welding process.

Some. However, it can't be called two protection welding, it is: self-protection welding.

Self-protection welding is also called ** welding, which should be automatic ** welding.

**Welding is a kind of welding, which is generally used to weld large workpieces such as oil pipelines, large boilers and so on. Such as automatic carbon dioxide shielded welding, automatic argon shielded welding, etc.

The difference between gas shielded welding and secondary shielded welding:

Gas shielded welding refers to the welding method of carbon dioxide or argon protection, without the use of welding rod and welding wire. CO2 welding efficiency is high, and argon shielded welding mainly welds aluminum, titanium, stainless steel and other materials.

The second welding process is suitable for all kinds of large-scale steel structure engineering welding of low carbon steel and low alloy high-strength steel, with high welding productivity, good crack resistance, small welding deformation, large range of adaptable deformation, and can be welded with thin plates and medium and heavy plates.

First adjust the current knob to the minimum, adjust the voltage knob to the maximum, test welding, do not move the voltage knob at this time, gradually increase the current, and stop until it can be welded normally; On the other hand, it is to adjust the current knob to the maximum first, and then adjust the voltage knob to the minimum, test welding, do not move the current knob, and gradually increase the voltage until it can be welded normally.

Turn both the current and voltage knobs to the minimum and gradually increase the voltage and current until you find a match that you think has the best weld formation, the softest sound, and something you can control. At this point, congratulations, you've found a way. You can adjust the current and voltage corresponding to various welding positions of vertical welding, flat welding, horizontal welding, and vertical welding.

Specific phenomena and causes.

Introduction of welding machines

The voltage is low, the right hand holding the gun will feel the stiffness of the head of the welding gun, the strong vibration of the head of the welding gun, the sound of bursting can be heard, there is resistance to moving the welding gun, and the welding wire is inserted into the molten pool through the mask, and there is a lot of splashing. This is because the voltage is too low, the wire feeding speed is much greater than the melting speed, and the arc ignites and then is extinguished by the welding wire.

The voltage is high, the head of the welding torch is too soft, there is almost no vibration, the welding torch can be moved as you like, and the welding wire floats above the molten pool through the mask, and a large molten ball is formed at the end, and sometimes there is a large molten droplet splash.

When adjusting the welding voltage knob, the welding voltage should be slowly increased, the melting speed of the welding wire will be accelerated, and the crackling sound of the explosion will gradually become a smooth sizzling sound; Observe the voltmeter and ammeter, if the current is lower than the predetermined value, first increase the welding current, and then increase the welding voltage; If the current is higher than the predetermined value, the welding voltage is lowered first, and then the welding current is reduced.

Summary. The specific reasons for this are as follows.

1. Most of the welding power sources of the second welding have flat characteristic output; However, most of the welding power sources of hand arc welding adopt the descending characteristics; Therefore, the external characteristics of the two power supplies are completely different;

2. The second welding also involves the controllable part of the power supply; This is not something that hand arc welding has;

3. The welding wire of the second shielding welding must be matched with shielding gas to give full play to the best welding effect, and manual welding does not need to be matched with shielding gas <>

Can the carbon dioxide gas shielded welding machine be used as an ordinary electric welding machine?

Hello, dear, happy to answer your <>

The carbon dioxide gas shielded welding machine cannot be used as an ordinary welding machine<> and the specific reasons are as follows: 1. Most of the welding electric clear letter accompanying sources of the two shielded welding have flat characteristic output; However, most of the welding power sources of hand arc welding adopt the descending characteristics; Therefore, the external characteristics of the two power supplies are completely different; 2. The second welding also involves the controllable part of the power supply; This is not something that hand arc welding has; 3. The welding wire of the second shielding welding must be matched with shielding gas to achieve the best welding effect, and manual welding does not need to be matched with shielding gas <>

The difference between a gas-fired secondary welding machine and a gasless secondary welding machine is the difference in gas when used. Let's take a closer look at the differences.

1. Gas welding machine

The gas welding machine, also known as MIG welding machine, needs to use inert gas (such as argon, helium, etc.) to prevent the welding area from chemically reacting with the oxides in the air, so as to ensure the welding quality. In addition, the gas welding machine can also use carbon dioxide gas for welding.

The advantage of the gas welding machine is that it can isolate the welding area from the air and prevent oxidation, so as to obtain high-quality welding results. At the same time, the gas welding machine can also carry out high-efficiency continuous welding, which can be suitable for welding large workpieces such as thick plates and heavy metals.

2. Gasless two-protection welding machine

Also known as flux-cored, this welding machine uses a welding material called a wire core. The core of the welding wire already contains chemical components that create a shielding gas and stop the oxidation of the air. Therefore, when using an airless secondary welding machine, there is no need to use additional inert gas.

The advantage of the airless secondary welding machine is that it can be applied to outdoor welding without the use of inert gas, which is more convenient. At the same time, the airless welding machine can also carry out vertical welding and reverse welding, which can be applied to steel structure, railway transportation and other industries.

Third, the scope of application of the second welding machine

The gas-fired two-protection welding machine and the gasless two-protection welding machine have their own characteristics, and the scope of application in different welding environments is different. Typically,The gas welding machine is suitable for the following occasions:

1.welding of larger workpieces or thick plates;

2.Welding requires high-quality workpieces, such as automobiles, etc.;

3.Environments that require high-efficiency, continuous welding.

The gasless two-protection welding machine is suitable for:

1.Welding is required in an outdoor environment;

2.Industries such as steel structures and railway transportation require high-quality and high-efficiency welding.

To sum up, the gas second protection welding machine uses inert gas to prevent oxidation reaction during welding, and is suitable for welding large and heavy workpieces; The airless secondary welding machine uses the welding wire core as a shielding gas, which is suitable for outdoor environments and high-quality welding. When choosing, choose according to your needs.