How to weld galvanized steel pipe welding cracking 10

Welding cracks generally occur in the transition layer from the hardened zone to the unheat-affected zone on one side of the HSS, and the cracks are in a regular ring, which is fundamentally parallel to the weld. Therefore, the following measures should be taken to prevent the occurrence of such cracks for hot-dip galvanized square pipes after welding.

After butt welding, the hot-dip galvanized square pipe immediately enters the pit furnace or box furnace of 600-7501 (pearlite changes the temperature zone) for thermal insulation treatment, the time is 203, and after the insulation is completed, it is cooled to below 5001 with the furnace and air-cooled;

The welding blank that has been baked is sealed for isothermal annealing, usually the sophisticated isothermal spheroidization annealing technology selected by the hot-dip galvanized square tube factory is 840-8701x3-46 ten 720-7401x3, the furnace is cooled to 5001 or less to bake, after annealing, both sides of the weld are abundant and changed to pearlite-soplet arrangement, and the hardness of some high-speed steel is 2070255983. Therefore, annealing after welding can improve the microscopic arrangement of the welded workpiece, eliminate the internal stress, that is, reduce the hardness, facilitate the cutting process, reduce deformation and deflection, and can eliminate cracking, etc., and the above methods can be useful to prevent the appearance of cooling cracking after welding.

It is recommended that the landlord find a roadside welder who can weld electric welding, take the galvanized steel pipe, it is easy to weld it quickly! If there is oxygen welding, it is better, and oxygen welding is stronger.

Summary. 01. Grinding before welding.

The hot-dip galvanized steel pipe must be polished off the galvanized layer on the surface before welding, mainly to prevent the zinc layer from evaporating during welding to produce a lot of white smoke, which is harmful to the human body; The second is to prevent the occurrence of bubbles, trachoma, false welding, etc., which makes the weld brittle and reduces the rigidity of the hot-dip galvanized steel pipe.

02. Groove size.

In order to weld through, the groove size of the galvanized pipe must be carefully handled before welding, and the more appropriate break size is between 60 and 65 °, and attention should be paid to leaving a certain gap, and the size of the gap is generally around the center.

How to weld hot-dip galvanized steel pipes.

01. Polishing the hot-dip galvanized steel pipe before welding, the galvanized layer on the surface must be polished off before welding, mainly to prevent the zinc layer from evaporating during welding to produce a lot of white smoke, which is harmful to the human body; The second is to prevent the occurrence of bubbles, trachoma, false welding, etc., which makes the weld brittle and reduces the rigidity of the hot-dip galvanized steel pipe. 02. In order to weld through, the groove size of the galvanized pipe must be carefully handled before welding, and the more appropriate break size is between 60 and 65 °, pay attention to leave a certain gap, and the size of the gap is generally around.

03. When selecting welding rods, the selection of welding rods should be selected according to the base material of the galvanized pipe, generally considering the ease of operation, it is recommended to choose J422. 04. When welding, in order to melt the zinc layer and vaporize and evaporate and escape from the weld, you can first move the end of the welding rod forward by 5 7mm, and then return to the original position to continue welding after the zinc layer is melted.

Summary. The possible causes of cracking are as follows:

1. During the welding process of the galvanized layer, because the melting point of zinc is too low, the gas generated by the evaporation of zinc hinders the flow of molten iron in the molten pool and forms defects, resulting in cracking.

2. Zinc vapor is mixed with molten iron to form slag inclusions and other defects, resulting in cracking.

3. The material of the base metal is very poor, and the current galvanized pipe material is very poor, which cannot meet the standard at all, and there are many sulfur and phosphorus impurities, and it will also crack.

Why does galvanized steel crack when welded and what is welded with.

Hello, I have seen your question for the round rental, and now I am speeding up the answer for you, please wait patiently for a while

The use of J422 electrode is generally the use of J422 electrode. The commonly used galvanized pipes are Q215A, Q215B, Q235A, and Q235B, which belong to the ordinary rough and dry low-carbon steel, and the J422 electrode is used to weld steel knots and ordinary carbon steel materials, so the J422 electrode can be used for the welding of galvanized pipes.

The reasons for cracking may be as follows: 1. During the welding process of the galvanized layer, because the melting point of zinc is too low, the gas generated by zinc evaporation hinders the flow of molten iron in the molten iron pool and forms defects, resulting in cracking. 2. Zinc vapor is mixed with molten iron to form slag inclusions and other defects, resulting in cracking.

3. The problem of the base metal attack material, the current galvanized pipe material is very poor, it cannot reach the standard sock ruler at all, and there are many impurities containing sulfur and phosphorus, and it will also crack.

I hope mine is helpful to you and have a great day! 

In our daily life, many people have seen galvanized steel pipes, so can galvanized steel pipes be welded? Many people have questions about this problem, today I will tell you about the relevant content of galvanized steel pipe when it can be welded, I hope it can help you, if you are interested, you can follow to understand it.

1. Can galvanized steel pipes be welded?

Galvanized steel pipe can be welded, but it should be noted that after the galvanized steel pipe is welded, the galvanized layer after welding should be polished and smoothed, if not, it will affect the quality of galvanized steel pipe, and it is easy to cause blistering and oxidation of galvanized steel pipe.

Second, about the use of galvanized steel pipes.

1. We have all heard of galvanized steel pipes, commonly used galvanized steel pipes are generally used in gas heating iron pipes, galvanized steel pipes can also be used as water pipes, but after a few years of use, a large amount of rust will be produced in the pipe, in fact, we do not advocate the use of galvanized steel pipes as water pipes, because galvanized pipes are not suitable for long-term in a humid environment, which is easy to rust and corrode.

1. As early as the sixties and seventies, the state began to ban galvanized steel pipes one after another, but at present, galvanized steel pipes are still used in the cold water pipes of many new residential areas, and galvanized steel pipes are also used in the hot water pipes of many residential areas. Since 2000, China's Ministry of Construction has begun to ban galvanized steel pipes, and there are still many questions about why we still use galvanized steel pipes.

2. Galvanized steel pipes are easy to rust and corrode, especially when installed in places with water, which will cause a lot of bacteria, and may also endanger the health of the human body in serious cases.

The above is a summary of the relevant content and information about galvanized steel pipes that can be welded, I hope it can help you. If you have other questions, you can leave a message at the bottom of the platform, and we will solve the problem in time, and finally if you have any questions about home or home decoration, you can pay more attention to Qeeka Home.

Summary. Kiss and kiss; It should be in the process of heating zinc, and the deformation of the high temperature causes the welding part to crack.

Why does galvanized steel crack when welded and what is welded with.

Kiss and kiss; It should be in the process of heating zinc, and the deformation of the high temperature causes the welding part to crack.

It should be in the process of heating zinc, and the deformation of the high temperature causes the welding part to crack. Generally, after galvanizing, welding will avoid similar situations, and the welding part of which slag tung position uses Robaru cold galvanized coating for anti-rust treatment. The first beam polishes off the welding slag, and then paints a cold galvanized, and then paints a silver-rich zinc, which can basically achieve the hot-dip galvanized Litan effect in both rust prevention and color.

What are the causes of weld cracking and the early treatment method: 1. Caused by unqualified quality of welding rods, Jianbi fiber lobbied to choose regular welding rods. 2. If the electrode does not match the base metal, it is recommended to consult the seller, such as welding Q235 material, and J422 electrode should be used.

3. The welding current is too large, and cracks are produced after cooling. It is recommended to choose an appropriate current and try to weld with a small current. There are three types of weld cracking, one is cracking, which is caused by high welding temperature.

The second is heating cracks, there are no cracks after welding, but cracks appear after heat treatment. The third is cold cracking, cracks generated during welding.

What should be paid attention to in steel structure welding: 1. Before welding, the operator should wear corresponding protective measures, such as work clothes, safety helmets, gloves, protective glasses, etc. Avoid welding slag splashing, cause burns, but also can protect arc light radiation, to avoid human poisoning.

2. Secondly, when welding combustible substances, the standing stone should be disposed of first and then welded according to the regulations to avoid causing fire. In addition, welding in a humid environment should also pay attention to the risk of electric shock. 3. Then when welding, we should pay attention to the length of the arc, mainly according to the type of welding rod, it is best to use a short arc to avoid the intrusion of harmful gases into the weld and affect the welding quality.

4. Finally, when welding, pay attention to the welding speed. It is usually related to the size of the electrode, the welding current, etc. It is recommended to maintain a uniform speed, which is conducive to the emergence of impurities and gases, and avoids porosity or slag inclusion in the weld.

In addition, the welding temperature should also be well controlled, and the leather manuscript should not be too high, too high will make the molten iron flow good and easy to flow, thus forming welding tumors, and the forming is not easy to control.