First of all, let's understand what is a welder?

Welders are a type of work that uses suitable welding methods, reasonable welding processes, appropriate welding equipment, and fillers of the same or different materials or even no fillers, with heating or pressure or both heating and pressure to tightly connect metal or non-metal workpieces. In fact, the welder is a very popular work, all walks of life are inseparable from the welder, although welding is a very easy to learn skills, but to use good depends on personal comprehension, coupled with theoretical and practical learning, the following we will start to learn about the problems commonly encountered in the welding process and solutions it!

NO.1

Sticky electrode how to do?

Sticky electrode is spot welding electrode and parts to form a non-normal welding and electrode and parts of the adhesion phenomenon, serious electrode is pulled out, cooling water flow to make parts rust.

The reasons for sticky electrode are about 4 points

1、The working surface of two electrodes is not parallel. This situation causes the electrode working surface and parts local contact, the electrode and parts contact resistance increases, which will make the welding circuit current has decreased. WeChat public number: welders, but the current is concentrated in the local contact point, the current density of the contact point is greater than the normal welding electrode working surface current density, resulting in the temperature of the contact point to the electrode and parts of the weldable temperature, the formation of electrodes and parts of the fusion.

2、The working surface of electrode is rough. Electrode working surface and parts can not be completely fit, only some parts protruding and parts contact. This situation will also cause the situation in (1).

3、Insufficient electrode pressure. Contact resistance and pressure are inversely proportional. Insufficient electrode pressure causes the contact resistance between the electrode and the part to increase, the contact part resistance heat increases, so that the electrode and the temperature of the contact surface of the part rises to the weldable temperature, forming a fused connection between the electrode and the part.

4、Welding gun cooling outlet water pipe connected to the reverse or cooling water circulation obstruction, electrode temperature increases, in continuous spot welding can cause electrode and parts fusion connection.

Solution

1、File the electrode head so that the working surface of the two electrodes is parallel and the surface is free of rough defects. Select the welding program as resharpening program (no current output), and observe whether the working surface of the two electrodes is parallel by emptying the welding robbery.

2、In the resharpening state, the welding will be beaten 5~10 times in the air, in order to forge the working surface of the two electrodes to increase the contact area within the specified diameter of the electrode head, and to improve the surface hardness.

3、Heat the working surface of the electrode with oxyacetylene flame to make the click working surface form an oxide layer (oxidation post), the oxidation post has good thermal stability and the melting point can reach 1300℃. It can improve the melting point of the working surface of the electrode, and at the same time destroy the weldability between the electrode and the parts.

4、Coat the working surface of the electrode with the red-dan configured by the welder to destroy the weldability between the electrode and the parts.

5、Adjust the electrode pressure and use the welding parameters of high pressure, hitting power source and short power-on time.

6、Clean the cooling water pipe regularly to ensure the flow of cooling water.

NO.2

When welding vertical seam, how to weld the most flat?

Stand welding with continuous arc welding forming is better, the current is 10% less than the current of flat welding, the angle is about 70 to 75 degrees. We generally use the sawtooth and crescent-shaped bar method, mainly for your own application. What is the reason for the small cracks that sometimes appear when welding vertical seams?

The causes of cracks may be multifaceted and can be found in the following areas.

1, the material is which type, according to which you should choose the matching welding material.

2, according to the material and the form of the joint, choose the appropriate welding construction specifications, if necessary, to determine the parameters of the welding construction process by test, multi-pass welding, but also pay attention to control the interlayer temperature.

3, according to experience, so thick two pieces of welding, should be preheated before welding.

Cracks in the steel pipe after welding the causes and solutions

Cracks appear for the following reasons:

1, the weld shrinkage stress is too large, easy to produce slow cracking.

2, the weld is not uniformly heated, prone to brittleness.

3、Welding method and sequence are not reasonable.

4, Poor control of interlayer temperature.

Preventive measures.

1, the first step is to choose a reasonable welding sequence, using symmetric welding.

2, multi-layer multi-channel welding, welding after each weld (not priming welding) to carefully handle the weld surface slag, oxide skin, to prevent the formation of defects in the next layer of the spoil weld.

3, adjust the cooling rate, the faster the cooling, the greater the deformation. Crystallization cracking tendency is also greater.

4, after welding to eliminate residual stress.

NO.3

Welded joint distortion

After welding, the spot welding surface is distorted from the plate by more than 25, and the distorted joints are prone to desoldering and dummy welding.

The main reason is that the upper and lower electrodes are not aligned, the point extremities slip when energized, the electrode extremities are poorly shaped, and the workpiece is not perpendicular to the electrode.

Solutions for distorted solder joints.

Check whether the upper and lower electrodes are aligned, set the torch right when welding, make the torch and the part vertical in welding, show the electrode end surface flat.

NO.4

Weld through

After welding the welding area perforation, parts are burned through, the reason is too small electrode end face, current and time is too much, there is a gap between the parts

Solution.

Adjust the parameters, resharpen the electrode head, and increase the pre-pressure time.

NO.5

Welding precautions

I. The length of the arc

The length of the arc is related to the type of electrode coating and the thickness of the flux. But all should take as short an arc as possible, especially low-hydrogen welding rod. Long arc may cause porosity. Short arc can avoid the atmospheric O2, N2 and other harmful gases into the weld metal, the formation of oxides and other undesirable impurities and affect the quality of the weld.

Second, the welding speed

The appropriate welding speed is to welding rod diameter, coating type, welding current, the heat capacity of the welded object, the beginning of the structure and other conditions have their corresponding changes, can not make standard regulations. WeChat public number:micro welders, to maintain a suitable welding speed, the slag can be well covered with molten pool. So that the molten pool of various impurities and gas have sufficient floating time to avoid the formation of slag and porosity of the weld. In welding, such as transporting the rod speed is too fast, when the welded part is cooled, the contraction stress will increase, so that the weld cracks.

Third, the selection of welding wire points

The selection of welding wire should be based on the type of steel being welded, the quality requirements of the welded parts, welding construction conditions (plate thickness, bevel shape, welding position, welding conditions, post-welding heat treatment and welding operations, etc.), cost and other comprehensive considerations.