What are the tips for welding technology? Basic operation skills of electric welding

In life, we inevitably have to weld, let's learn what are the operating skills of electric welding technology.

01 Before welding, the most important thing is to adjust the welding current, if the current is too small, the welding will be more troublesome, if the welding current is too large, it will cause the welding rod to melt too quickly.

02 Before welding, the selection of welding rods is also very important, pay attention to the selection of welding rods that match the material of welding items to improve welding efficiency.

03 When welding, the dust is very large, and the temperature is too high, and the light is too bright, so it is necessary to take protective measures in advance to avoid causing damage to the eyes.

04 When welding, the hand needs to be kept stable and welded, and the arms must be clamped tightly to avoid shaking, so that the welding can be uniform and beautiful.

05 When welding, it is generally used to weld zigzag and dot type, so that the welded seam texture is clearer.

06 When welding, keep the welding rod and the iron plate at an angle of 45 degrees, which is conducive to the uniform distribution of molten iron, and the weld is smooth. When performing the upward welding operation, because the molten iron is easy to fall, it is necessary to take the form of spot welding, so that the sintering will be more firm.

07 When carrying out flat welding in electric welding, it should be noted that the interface should be as smooth as possible, this is not something that can be done overnight, do not shake your hands when welding, do not keep moving your eyes, and the welded works are naturally good.

08 Contact arc striking - scratch method.

First align the end of the electrode with the weldment, and then scratch the electrode on the surface of the weldment, when the arc is drawn and then the metal has not begun to melt in large quantities, the distance between the end of the electrode and the surface of the weld is maintained at a distance of 2 4mm, and the arc can be burned stably.

If the welding rod and the weldment stick together, as long as the welding rod is shaken left and right a few times, it can be separated from the weldment, if it can not be separated from the weldment at this time, the welding tong should be relaxed immediately, the welding circuit is disconnected, and the welding rod is slightly cold before being removed.

09 Contact Arc Initiation - Percussion Method.

When the end of the electrode touches the surface of the weldment, the electrode is quickly lifted and kept at a certain distance, which immediately ignites the arc. When operating, the welder must master the time and distance of the wrist up and down movements.

The basic operation skills of electric welding are:Keep it clean, check your airflow, check your equipment, working conditions.

Keep it clean. Before preparing the surface of the material and material for welding, it can prove to be a clean weld as important as the weld itself. If proper care is not taken, the clear finger liter imitation cleaning leads to surface contamination and porosity, which needs to be reworked or replaced at the expense of time and money.

Check your airflow. Monitor gas protection from your flow. The stronger the airflow, the more restless the air, which can cause contaminants to agitate with the weld pool, resulting in impure welding. While traffic can vary, it's important to choose the right traffic for each application.

Check your device. Over time, the hose may leak or the wiring may come into contact or wear out. Checking all connections in a striking arc will help ensure that you get the exact flow of your air shield.

Working conditions. The welding shop will be hot, but you should open the door and let the breeze think twice. You must monitor your workplace for strong air currents or water currents that may affect the melt pool or gas protection.

Brief description of electric welding:

Electric welding is a welding operation that uses the welding rod to melt the metal parts at high temperature through the arc to the place where they need to be connected. Its working principle is: through the commonly used 220V or 380V voltage, through the transformer in the welding machine to reduce the voltage, enhance the current, and make the electrical energy produce a huge arc heat to melt the electrode and steel, and the welding rod melting makes the integration between the steel higher.

Arc welding is the most widely used welding method, including hand arc welding, submerged arc welding, tungsten gas arc welding, etc.

Electric welding is an economical, applicable fiber-only and technologically advanced method in the processing of material joining. Welding with electricity can be achieved between almost any two metallic materials, as well as between certain metallic and non-metallic materials. It can be realized to make a large, economical and reasonable structure from small to large.

1. Storage of welding rods:

1. All kinds of welding rods must be classified and stored in different grades to avoid confusion, and should be stored in a dry and well-ventilated warehouse, and should be placed at least 300mm away from the ground and wall to prevent moisture deterioration.

2. Because the coating is easy to be damp, the process performance of the welding rod after moisture deteriorates, and the hydrogen in the moisture is easy to cause porosity and cracks in the weld, so the welding rod must be dried before use to reduce the hydrogen content of the welding rod, generally using 350 450, heat preservation for 1 2 hours, drying.

2. Operation:

1. After the workpiece is combined, the spot welding is firm, and the weld is welded, the width and depth ratio of the weld is 2 3, and the width of the weld is generally doubled. The starting weld refers to the part that has just begun to be welded, and the arc should be slightly lengthened after the arc is struck, and the necessary preheating of the weld end should be carried out, and then the arc length should be appropriately shortened for normal welding.

2. Weld closure means that when a weld is welded, the arc pit at the end should be filled, if the arc is immediately pulled off at the end, the arc pit below the surface of the weldment will be formed, and the strength of the weld at the end will be weakened if it is too deep, resulting in cracks. Therefore, no craters are allowed at the end of the process, and the craters should be filled until they are filled.

3. Due to the limitation of the length of the welding rod, the joint can sometimes not complete a weld with a welding rod, and the beginning of the weld is required to be slightly lower, and the arc is slightly ahead of the beginning of the weld when the joint is welded, and the arc is slightly elongated to lead the arc to the beginning, and cover the end of the front weld, and then move along the welding direction after the weld at the beginning is flattened.

4. The width of the weld is generally made by zigzag or crescent-shaped strip method, the weld welded by this method has a higher reinforcement height, the metal melts well, has a long holding time, and is easy to make the gas precipitation and slag float to the surface, which is good for improving the quality of the weld.

Weld thickness The first layer of welds The welds of the other layers.

Welding rod diameter Welding current (a) Welding electrode diameter Welding current (a).

When welding the second layer, the first layer of slag is removed first, and then the welding is carried out with a welding rod with a larger diameter and a larger welding current. In order to ensure quality and prevent deformation, the welding direction between the layers should be reversed, and the weld joints should also be staggered from each other.

What are the basic tips for welding? As follows:

The novice learns the initial stage of electric welding is to practice flat welding, flat welding, welding skills are, one to control the size of the current, the other to adjust the angle between the welding rod and the welding workpiece in the actual welding, if the current is too large, the angle of the welding rod and the workpiece is at a right angle of 90 degrees.

If you feel that the current is too small, increase the distance between the electrode and the workpiece, and tilt the electrode to 70 to 80 degrees to weld. If the current is too large, if the arc is not controlled, it will lead to too high temperature, and the workpiece will be burned through and burned out.

Novices learn the initial welding skills and precautions of electric welding:

1. The welder must undergo professional training, pass the examination and hold a safety operation certificate before being allowed to operate independently (during the apprenticeship training, it can be gradually operated under the supervision of the master).

2. Welders must wear work clothes and use protective equipment (including heat-insulating gloves, insulating rubber boots, and masks) in accordance with the regulations, and the workplace must meet the safety requirements.

3. Before work, it is necessary to check in detail whether the welding machine is normal, whether the insulation is good, and the shell of the welding machine must have good grounding.

4. The power cord and the secondary circuit must be complete and well insulated, and shall not be replaced by other objects. It is strictly forbidden on equipment, steel cables, pipes, containers and metal structures of the plant.

5. In the fire ban area and the parts with the possibility of flammability and explosion or toxic places, the fire must go through the formalities and a complete fire permit, and the construction can only be carried out after the analysis is qualified and approved.

6. The welding tongs must be well insulated, and the wiring should be firm and wrapped to avoid electric shock caused by loosening.

7. No flammable and explosive materials shall be stored in the welding workplace, and measures shall be taken to prevent welding slag from falling and causing other dangers.

8. If the wiring or electrical equipment fails, it should be overhauled by an electrician, and other personnel are prohibited from messing around.

Electric welding refers to the use of electrical energy, through heating or pressure, or both, and with or without filler materials, so that the weldment can achieve atomic bonding. The processing equipment used for electric welding is called an electric welding machine.

According to the different heating and pressurization conditions during welding, welding methods are usually divided into three categories: fusion welding, pressure welding and brazing.

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

The welding techniques for beginners are as follows:

When welding, the hand should be kept smooth and smooth, and the arms must be clamped to avoid shaking, so that the welding is uniform and beautiful.

When welding, the angle between the electrode and the iron plate is kept at an angle of 45 degrees, which is conducive to the uniform distribution of molten iron, and the burned electrode is smooth. In the upward welding operation, because the molten iron is easy to fall, it is necessary to use the form of spot welding, so that the soldering is more firm.

When the electrode moves to the top of the weld, it moves in a circle at the arc pit until the arc pit is filled, and then the arc is broken. When replacing the electrode or temporarily stopping the arc finish, when moving the electrode to the end of the weld, stop at the arc pit for a while, slowly lift the arc, and then lead to the base metal groove at the edge of the weld. At this time, the molten pool will gradually shrink, and there will generally be no defects after solidification.

Contraindications for electrode operation:

The use of percussion method is not easy for beginners to master, and it is generally prone to arc extinguishing or short circuit, which is the reason why the speed is not mastered and a certain distance is maintained.

If the electrode is pulled up too fast or raised too high during operation, it cannot be triggered or the arc is extinguished only when burning. On the contrary, if the action is too fast, the welding rod will bond with the weldment, resulting in a short circuit in the welding ring.

If the welding rod sticks to the weldment during arc initiation, the welding tong should be loosened immediately. If the short-circuit current is too large, it will cause the short-circuit current of the welding machine to burn out. The speed at which the electrode moves has an important impact on the quality of the weld seam and the welding efficiency.

The commonly used welding methods are as follows:

1. Linear transport method. When this method of transportation is adopted, the welding rod does not swing horizontally, but moves in a straight line along the welding direction. It is commonly used for butt flat welding of grooves, first layer welding of multi-layer welding or multi-layer multi-pass welding.

2. Straight-line reciprocating method. When welding with this strip method, the end of the electrode swings back and forth along the longitudinal direction of the weld. It is characterized by fast welding speed, narrow weld seam and fast heat dissipation. It is suitable for the first layer of multi-layer welding with large gaps between thin plates and joints.

3. Zigzag transport method. In this method of welding, the end of the electrode is zigzag and moves forward, and stops on both sides for a while. The purpose of the oscillation is to control the flow of the molten metal and obtain the necessary weld width to obtain a better weld formation.

This method of transporting bars is widely used in production, and is mostly used for the welding of thick steel plates, the butt joints of flat welding, vertical welding, vertical welding and the fillet joints of vertical welding.

4. Crescent-shaped transport strip method. When welding with this rod method, the end of the electrode swings left and right in a crescent-shaped shape along the welding direction. The speed of the swing is determined according to the position of the weld, the form of the joint, the width of the weld and the value of the welding current.

At the same time, it is necessary to stay on both sides of the joint for a short time to allow sufficient penetration at the edge of the weld to prevent undercut.

The characteristics of this method are that the metal melts well, has a long holding time, the gas is easy to precipitate, and the slag is also easy to float to the surface of the weld, and the quality of the weld is higher, but the residual temperature of the welded weld is higher. The scope of application of this method is basically the same as that of the zigzag method.

5. Triangle transport method. When welding with this transport method, the end of the electrode moves in a continuous triangle and constantly moves forward. According to the different swing forms, it can be divided into two kinds of oblique triangle and regular triangle, and the oblique triangle transport strip method is suitable for the T-joint weld and the horizontal weld with groove in the position of flat welding and upward welding, and its advantage is that it can control the molten metal by the swing of the welding rod, and promote the weld to form well.

The regular triangle strip method is only suitable for the vertical welding of the butt joint and the T-joint weld of the bevel opening, and the characteristics are that it can weld a thick weld section at one time, and the weld is not easy to produce defects such as slag inclusion, which is conducive to improving production efficiency.

6. Circle-shaped transport method. When welding with this method of transporting bars, the end of the electrode continuously moves in a positive circle or oblique circle, and constantly moves forward. The positive circle transport strip method is suitable for welding flat welds of thicker weldments, and its advantages are that the molten pool exists for a long time and the metal temperature of the molten pool is high, which is conducive to the precipitation of oxygen, nitrogen and other gases dissolved in the molten pool, and is convenient for the slag to float.

The oblique circle strip method is suitable for the horizontal weld of T-joint weld and butt joint in flat and vertical positions, and its advantage is that it is conducive to controlling the molten metal from the influence of gravity and causing the phenomenon of spillage, which is conducive to the formation of weld.