95What are the characteristics of CO2 gas for welding?

The welding wires used for welding mild steel and low alloy steel are: H08MNSIA, H08MNSI, H10MNSI.

The welding wires used for welding low alloy steel strength steels are: H08MN2SIA, H10MNSSIMO, H10MN2SIMOA.

The welding wires used to weld bainite steel are: H08Cr3Mn2MoA.

The wires used for welding low spatter resistant microporosity welds are: H0Cr18Ni9, H1Cr18Ni9, H1Cr18Ni9Ti.

The welding wires used for welding stainless steel sheets are: H0Cr18Ni9, H1Cr18Ni9, H1Cr18Ni9Ti, H1Cr18Ni9NB.

Flux-cored wire. The flux-cored wire is rolled into a round tube with a thin steel strip, which is filled with a component of powder to draw the wire. Flux-cored wire welding is used to form a joint protection of air slag, the weld is well formed, and the welding spatter is small.

Commonly used flux-cored wires are: YJ502, YJ507, YJ507CUCR, YJ607, YJ707.

There are many process parameters that affect carbon dioxide gas shielded welding, but the only ones that the welder can adjust by themselves are the welding voltage, welding current, welding wire diameter, gas flow, and welding wire extension length;

CO2 gas shielded welding uses a short-circuit transition, so the welding specification area for each diameter of the wire is wide, in which the welding current and welding voltage must be matched.

The magnitude of the welding current mainly depends on the wire feed speed. The faster the wire feed, the greater the current for welding. The welding current has the greatest effect on the penetration depth of the weld.

When the welding current is 60 250A, that is, when welding in the form of short circuit transition, the weld penetration is generally 1mm 2mm; It is only above 300 A that the penetration depth increases significantly.

(1) oxidation of CO2 gas;

2) Porosity due to the cooling effect of the air flow, the molten pool solidifies quickly, and it is easy to produce porosity in the weld. However, it is conducive to thin plate welding, and the deformation after welding is also small.

3) Cold crack resistanceDue to the low hydrogen content of the welded joint, CO2 gas shielded welding has high cold crack resistance.

4) Splashing is the main disadvantage of carbon dioxide gas shielded welding.

Features of C02 gas shielded welding:

1.The welding speed is fast, the arc initiation performance is good, and the melting wire is twice as fast as manual arc welding per unit time.

2.The energy is concentrated, the arc is easy to start, and the continuous wire feeding arc is not interrupted.

3.It has a wide range of welding, and can be welded with low carbon steel, high strength steel, and ordinary cast steel.

4.Welding, the weld has low hydrogen content, good crack resistance, and small thermal deformation.

5.The deposition efficiency is high, the deposition efficiency of hand arc welding electrode is 60%, and the deposition efficiency of CO2 welding wire is 90%.

6.The large depth of dissolution can be applied to three times that of hand arc welding, and the amount of groove processing is small.

Compared with manual welding: the wind resistance is poor, and the equipment is more complicated.

Introduce the working principle of carbon dioxide gas shielded welding, and what parts of the equipment are composed?

Carbon dioxide. According to the different heating and pressurization conditions during welding, the welding method is usually divided into three categories: fusion welding, pressure welding and brazing.

1. Fusion welding is a method of heating the metal at the weldment joint to a molten state during the welding process, and generally completing the welding without pressure. During fusion welding, the heat source quickly melts the metal at the weldment seam and the filler metal added if necessary to form a molten pool, which extends with the movement of the heat source and forms a weld after cooling.

Fusion welding using electric energy is divided into arc welding according to different methods of electric heating.

Electroslag welding, electron beam welding, and laser welding.

Several. Fusion welding has a wide range of applications and is most commonly used in various welding methods, especially arc welding.

2. Pressure welding is a welding method that connects the seams of weldments together under pressurized conditions. In the process of pressure welding, no filler metal is added. According to the different welding mechanisms, pressure welding can be divided into resistance welding, high-frequency welding, diffusion welding, friction welding, and ultrasonic welding.

Wait. Among them, resistance welding is the most widely used. Most pressure welding methods do not have a melting process, and there is no burning of beneficial alloying elements and the immersion of harmful elements into the weld as is the case with fusion welding. However, the welding conditions of pressure welding are harsh, and the application surface is narrow.

3. Brazing is a welding method that uses a material with a lower melting point than the weldment to melt the head of the stool to bond the weldment, and then connects the weldment seams together after cooling.

Hello, the effects of CO2 welding gas on welding are as follows:

1. Oxidation: It is not suitable for metals that are easy to oxidize, such as early rust steel, titanium, etc., so CO2 welding can only be used to weld carbon steel and low-alloy steel;

2.Porosity: CO2 gas itself will increase the gas content in the melt pool, and if it does not overflow in time, it is easy to form porosity defects;

3.Splash: CO2 gas shielded welding is prone to spatter defects during the welding process.

Hope, thank you.

The arc welding method with carbon dioxide gas as shielding gas is known as carbon dioxide gas shielded welding, referred to as carbon dioxide welding.

Carbon dioxide gas shielded welding has the characteristics of no combustion

1.Carbon dioxide gas is cheap and easy to obtain, and consumes less electricity, which is an economical and convenient welding method for automatic production;

2.High production efficiency. The welding current density is large, the welding wire melting rate is high, the base metal penetration depth is large, for the steel plate of about 10 mm, it can be welded directly without opening the groove, and the slag after welding is very small, and the slag can be generally cleared, and the welding quality is stable;

3.The current density is large, the arc heat is concentrated, and the deformation of the workpiece after welding is small;

4.It is less sensitive to oil and rust, which can reduce the cleaning workload of workpiece and welding wire;

5.The hydrogen content of the weld metal is small, and the tendency to produce cold cracks is small when welding low-alloy high-strength steel.

6.There is a lot of spatter, the weld forming is not beautiful enough, and it takes time to clean up the spatter;

7.Carbon dioxide is weakly oxidizing, so it cannot be used to weld chemically active metals such as aluminum and magnesium.

1: Bright arc operation. Good visibility of the welding site. Easy weld alignment.

2: Low welding cost. C02 gas ** is cheap, and the comprehensive welding cost is electrode hand arc welding; About 40% of automatic submerged arc welding.

3: High welding current density. High deposition efficiency of welding wire; There is almost no welding slag, which reduces the labor intensity of slag removal.

4: The arc heating is concentrated, and the heating area is small. Combined with the cooling effect of carbon dioxide gas, welding can be reduced. Stress and deformation. Reduces burn-through and deformation of thin sheets.

5: The second-protection weld has good pitting and rusting ability; Low hydrogen content in the weld; Good crack resistance.

6: Wide adaptability, that is, thin wire short circuit transition welding thin plate and full-position welding;

It can also be used for coarse wire jet transition welding of large and thick plates.

7: Welding spatter is large; Poor weld formation (especially for CO2 single gas solid core wires); The welder is complex; Welding machine ** high;

8: Poor wind resistance. Second, the welding can not be welded in windy occasions.

Now there are still people who doubt the cost of second welding?

Don't you know that science and technology are the primary productive forces?!

Let's talk about welding consumables first, the second guarantee welding wire is 8 yuan a kilogram, and the welding rod is 6 yuan a kilogram, which seems to be cheap.

You have to see how much filler metal is left in the weld after welding, and the same amount of filler can be compared.

1. The coating on the outside of the welding rod, and finally the welding slag and shielding gas, do not belong to the filler metal.

2. Each electrode has a welding rod head, at least 5 cm, which has to be thrown away, and does not belong to the filler metal.

3. The welding rod has a large spatter and the metal that splashes out does not belong to the filler metal.

In addition, the welding rod needs to be dried, the oven, the insulation barrel, the electricity for heating, and the discarded electrode head.

It also has to talk about the power consumption of welding, the same welding effect, the heat input of the second guarantee welding is small, that is, the cost of electricity is less, and the inverter welding machine is more energy-saving.

Let's talk about efficiency and speed.

1. No need to bake welding rods, save time and reduce one labor.

2. There is no need to change the welding rod, and there is no need to start the arc from the new, saving time 3. There is no need to knock on the welding slag, at least reduce a small worker.

4. In terms of welding speed, the second protection welding is three times that of the welding rod. (Just this one, a welder can top three, you calculate, how much labor savings!) ）