02-06

What is the main job of a welder?

2023-02-06

What is a welder? Engaged in the work mainly includes: (1) Installation and adjustment of welding and cutting equipment and process equipment; (2) Operate welding equipment and perform welding; (3) Use special welding rods, welding equipment and tools to weld pipes, plates, rods and wires made of cast iron, copper, aluminum, stainless steel and other materials; (4) Use gas cutting machinery or hand tools to cut straight lines, grooves and irregular lines of metal workpieces; (5) Maintain the equipment and process equipment, and eliminate the general faults during use. Are welders studious? Welder textual research related to the development of information: Welder's work permit (special operation permit): the whole process of melting welding and thermal cutting (electric welding, gas welding, arc welding, electric welding and gas cutting, and other) is also called work permit. The issuing agency-Emergency Management Department [1], a card similar in appearance to an ID card, is also called welder's IC card and welder's work permit for the whole country. It takes three years to review and six years to renew the certificate. Welder Grade Certificate (Professional Qualification Certificate): It represents the level of your welding technology. The higher the registration, the higher your technology, the higher the salary given by the employer. The welder professional qualification certificate is divided into five levels, namely five (primary), four (intermediate), three (advanced), two (technician), one (senior technician). The welder grade certificate does not need annual examination, but is passed once and is valid for life. Expansion information: Conditions for 1. declaration of welder license: (1) At least 18 years old and not exceeding the national legal retirement age; (2) Experienced by the community or medical institutions at or above the county level to be healthy and qualified, and there is no organic heart disease, Meniere's disease, vertigo, hysteria, parkinsonism, psychosis, dementia and other diseases and physiological defects that hinder the corresponding special operations; (3) Having a junior high school level or above; (4) Have the necessary safety technical knowledge and skills; (5) Other conditions specified for corresponding special operations. Information to be prepared for registration of welder's certificate (new): 1. One scanned copy of the original ID card (front and back); 2.3 1-inch electronic photos (white background); 3. One scanned copy of graduation certificate (junior high school or above); The above information also needs to be provided in electronic version. If there is an electronic version, there is no need to provide paper data. 2. conditions for applying for professional qualification certificate: over 1.18 years old and under 55 years old 2. Good health, no epilepsy, mental illness, heart disease, sudden fainting, color blindness and other diseases and physiological defects that hinder electrical work. 3. Have the post operation certificate for this type of work (this condition is only required for some types of work) Intermediate (one of the following conditions can be met) 1. Have the same type of job operation certificate (only for some types of work need this condition) 2. Have the primary certificate of the same type of work 1. Have the post operation certificate of the same type of work (this condition is only required for certain types of work) 2. Have the intermediate certificate of the same type of work 3. examination through the requirements: The welder's operation certificate theory examination has a full score, 80 points pass, the duration is two hours, and there is a free make-up examination opportunity; the total score of the practical examination is 80 points. The welder grade certificate theory examination is based on a percentile system, with 60 points passing, and the duration is one and a half hours; the total score of the practical examination is also 60 points passing.

02-03

What do welders need to learn?

2023-02-03

Welding learning What do welders need to learn? Welding theory comes from practical operation, and the summarized theory guides the operation. Only skill operation and theory are closely combined to do a good job of "welder". The theoretical knowledge of welding is very rich and extensive. Many electric welders know too little about welding knowledge in their initial work. Most welders only know the fur from some old masters in the process of passing on art. They only master a relatively single operation technology and do not know how to solve welding problems. Such as the use of carbon steel welding rod welding stainless steel material, it will cause the weld formation is very poor, which is due to the stainless steel material compared with carbon steel material thermal conductivity is poor, the arc formation of the molten pool is not easy to solidify. The second point, learn to master the knowledge of Welding materials The welding process will come into contact with a lot of metal materials, each material has its characteristics, such as the mechanical properties of metal materials have strength, plasticity, hardness, toughness, etc.; metal physical properties have density, melting point, thermal expansion, thermal conductivity, Electrical conductivity and magnetism. These are closely related to the welding process. Such as austenitic stainless steel in welding, due to its physical characteristics of thermal expansion coefficient, large deformation; poor thermal conductivity, weld appearance forming is difficult to control. Therefore, stainless steel welding should adopt small line energy, small current short arc welding, speed up the cooling rate, make it stay in the sensitized temperature zone for a short time, strictly control the interlayer temperature, prevent intergranular corrosion, reduce welding stress and deformation. Avoiding welding defects can also be analyzed from macro to micro combined with theoretical knowledge. For example, welding pores on the construction site are theoretically divided into three types: hydrogen pores, nitrogen pores and CO pores. Through the macro characteristics of the three types of pores, the on-site weld pores are identified and qualitatively identified. The on-site and welding conditions are analyzed in combination with the theoretical causes of qualitative pores, and the causes and overcoming measures are found to avoid the generation of pores. In this way, many on-site welding phenomena can be answered through the research and analysis of theoretical knowledge. At the same time, the development of Welding materials is endless, and welders need to study carefully in order to become a "senior welder".

02-01

What are the welding difficulties of aluminum alloy

2023-02-01

Welding difficulties What are the welding difficulties of aluminum alloy 1) Whether it is regular argon arc welding or brazing, if the forming method of aluminum alloy is casting, because it contains many impurities, it will add a lot of welding influence to the welding, so it is easy to produce pores when argon arc welding cast aluminum. At this time, it is necessary to use Welding materials such as low-temperature welding wire argon arc welding that can cover the pores. If it is brazing welding, the general Welding materials will lead to poor forming and welding failure, because the welding of castings is very poor, this time can be used 53 low temperature aluminum welding rod gas welding. 2) Aluminum alloy in special components such as aviation aluminum, with heat treatment state of 6 series aluminum alloy, they are prone to cracks in welding, welding requirements are very high, because the composition of these materials and heat treatment state makes the brazing performance becomes very poor. 3) In the process of welding, if this aluminum alloy is extruded or forged, it is better to weld, but aluminum is a relatively active metal, which is easy to oxidize at all times in the welding process, which is also an important reason for increasing the difficulty of aluminum welding. 4) Aluminum is a good thermal conductor and heat sink. Whether it is welding or brazing, the upper temperature of the temperature is much more troublesome than that of ferrous metals. There are several difficulties in aluminum alloy welding 1) Whether it is regular argon arc welding or brazing, if the forming method of aluminum alloy is casting, because it contains many impurities, it will add a lot of welding influence to the welding, so it is easy to produce pores when argon arc welding cast aluminum. At this time, it is necessary to use Welding materials such as low-temperature welding wire argon arc welding that can cover the pores. If it is brazing welding, the general Welding materials will lead to poor forming and welding failure, because the welding of castings is very poor, this time can be used 53 low temperature aluminum welding rod gas welding. 2) Aluminum alloy in special components such as aviation aluminum, with heat treatment state of 6 series aluminum alloy, they are prone to cracks in welding, welding requirements are very high, because the composition of these materials and heat treatment state makes the brazing performance becomes very poor. 3) In the process of welding, if this aluminum alloy is extruded or forged, it is better to weld, but aluminum is a relatively active metal, which is easy to oxidize at all times in the welding process, which is also an important reason for increasing the difficulty of aluminum welding. 4) Aluminum is a good thermal conductor and heat sink. Whether it is welding or brazing, the upper temperature of the temperature is much more troublesome than that of ferrous metals.

01-30

Beginner welding should pay attention to what problems

2023-01-30

01-26

How to Solve Plate Welding Deformation

2023-01-26

Plate welding How to Solve Plate Welding Deformation The welding deformation of the steel plate is difficult to repair, and prevention is the main method, that is, the use of reasonable welding methods to prevent deformation in the welding process. Use symmetrical welding as much as possible. For work with symmetrical welds, it is best to weld symmetrically by pairs of welders. In this way, the deformation caused by each weld can be partially offset. 2. Sub-section back welding method This method is suitable for the welding of medium plate or thin steel plate. Its advantage is that the intermediate heat dissipation is fast and the temperature difference between the two ends of the weld is reduced. The temperature of the weld heat affected zone will not increase sharply to reduce or avoid thermal expansion deformation. 3. Alternating welding method This welding method is basically the same as the jump welding method, except that each section of the welding distance is elongated, which is especially suitable for thin plates and long welds. 4. The symmetrical method in the middle is suitable for weldments with short welds. In order to reduce deformation, the welding is finished at one time from the center to both ends. 5. Rigid fixed method Rigid fixed method to reduce deformation is very effective, and welding without excessive consideration of the welding sequence. The disadvantage is that some large parts are not easy to fix, and after the removal of the fixed after welding, the weldment still has a little deformation and a large residual stress. This method is suitable for welding thin-walled materials with thickness less than 6mm and good toughness. 6. Heat dissipation method Heat dissipation method is also called forced cooling method, that is, the heat at the welding place is quickly dissipated, so that the metal heating surface near the weld is greatly reduced, and the purpose of reducing welding deformation is achieved. 7. Hammering weld method Hammering weld method, that is, knocking the weld with a round head hammer, can reduce welding deformation and stress. How to weld thin plate welding? 1, the use of suitable welding machine, such as ZX7-and other small inverter welding machine. 2. Use a suitable electrode, such as a mild steel electrode with a diameter of 2.5mm. 3. Adjust the welding machine to the left and right welding current. 4. Do a good job of anti-deformation of thin iron plate. 5, try to choose flat welding. 6, each welding, stay the appropriate cooling time of the molten pool, and then weld the second time. 7. When welding, master the welding angle.

01-24

What should I pay attention to when welding aluminum alloy?

2023-01-24

Welding aluminum material What should I pay attention to when welding aluminum alloy/? Aluminum alloy material, high strength and light weight. The main welding process is manual MIG welding and automatic MIG welding, its base metal, welding wire, shielding gas, welding equipment. An aluminum alloy is an alloy composed of aluminum as a matrix element and one or more alloying elements. Because the heat energy of the tungsten argon arc welding torch is relatively concentrated, the arc combustion is stable, the weld metal is dense, the strength and plasticity of the welded joint are higher, and the quality of the joint is better, so it is the most commonly used method of welding aluminum alloy. In addition, when we weld aluminum alloy, we also need to pay attention to the following six points: High (I) thermal conductivity The thermal conductivity and specific heat capacity of aluminum alloy are more than twice that of carbon steel and low alloy steel. The thermal conductivity of aluminum is more than ten times that of austenitic stainless steel. During the welding process of the welding gun, a large amount of heat is quickly conducted to the inside of the base metal, and it is difficult to form a molten pool. Therefore, energy concentration and high power should be used, which can also be preheated according to the structure size, ambient temperature and other conditions; (II) without color change When the molten metal of aluminum alloy welding pool changes from solid to liquid, there is no obvious color change, which is different from the red color of steel before melting, which will bring inconvenience to the operation of the welding gun. Can not accurately determine when the groove base metal began to melt, molten aluminum surface tension is small, low strength, good fluidity, which is easy to cause the weld metal collapse or burn through. Therefore, aluminum welding operators are required to have more skilled operation skills and be good at using small changes in the surface of the molten pool to judge the heating temperature of aluminum; Strong (III) oxidation ability Aluminum and oxygen affinity is very strong, aluminum in the air easily with the oxidation of the formation of dense and strong film, its melting point as high as ℃ far more than the melting point of aluminum and aluminum alloy. And the relative density of the aluminum oxide film is larger, about 1.4 times that of aluminum. In the welding process using a welding torch, the aluminum oxide film will hinder the good bonding between metals and easily cause slag inclusion. Alumina film will also absorb moisture, welding will promote the formation of pores in the weld. Therefore, the oxide on the surface of the weldment must be strictly cleaned before welding and prevent re-oxidation during the welding process; (IV) hot cracking tendency The linear expansion coefficient of aluminum alloy is about 2 times that of carbon steel and low alloy steel. The volume shrinkage on solidification of aluminum is large, amounting to 6.5%, while that of iron is 3.5%. The strength of molten aluminum alloy is low at high temperature. If the process measures are improper, the welding seam and near-seam area will produce great welding stress, restraint stress and thermal stress during the cooling process. As a result, the aluminum welding pool is prone to produce shrinkage, shrinkage, thermal cracking and high internal stress during solidification; (V) Easily Evaporated and Burned Aluminum alloy contains low boiling point elements, such as magnesium, zinc, manganese, etc., under the action of high temperature arc, easy to evaporate and burn, thus changing the chemical composition of the weld metal, so that the performance of the weld is reduced; High stomatal sensitivity of (VI) The liquid molten pool of aluminum alloy is easy to absorb hydrogen and other gases, and a large amount of gas dissolved at high temperature is too late to precipitate in the process of cooling and solidification after welding of the welding torch, which will form pores when gathered in the weld. The moisture in the arc column atmosphere, the Welding materials and the moisture adsorbed by the oxide film on the surface of the base metal are all important sources of hydrogen in the weld. Therefore, it is necessary to clean the base metal groove and welding wire before welding.

01-19

How to weld stainless steel and copper

2023-01-19

Welded copper How to weld stainless steel and copper Stainless steel pipe and copper pipe welding is divided into the following welding methods according to welding requirements 1. regular flame welding, which requires high-silver welding wire such as Viodin to be welded with Viodin-F solder paste, or welding wire replacing silver to be welded with Viodin-F solder aid. Solder aid plays an auxiliary role in welding. When welding with 46, it can be welded without solder aid under the premise of mastering the operation skillfully, because the surface of 46 is equipped with solder aid. 2. Argon arc welding. When using argon arc welding, one requirement is to have a certain diameter and thickness for the structural size of the parent pipe material. If it is a small thin pipe, it is not suitable, because the operation of transporting gun is not as convenient as gas welding. In addition, welding thin material is not very easy to operate. 3. Then there is the dissimilar metal welding of red copper and stainless steel. If argon arc welding is used to operate, it is necessary to select the viodin brass argon arc welding wire suitable for welding between the two metals. The brass argon arc welding wire mentioned here is not the brass welding wire for gas welding, but the brass welding wire for argon arc welding, of which viodin is one of them. First of all, several welding options are used for brazing welding: 1, high silver welding wire work melting point is relatively low operational price is relatively high. 2. Viodin is used to replace high silver welding wire welding to solve Monel cupronickel carbon steel rust steel and the above-mentioned metal dissimilar welding strength is higher than non-high melting point. Copper and stainless steel welding wire is enough. Welding rod (coveredelectrode) During gas welding or electric welding, the metal strip that melts and fills the joint of the welded workpiece. The material of the electrode is usually the same as the material of the workpiece. According to different situations, welding electrodes have different classifications, and welding electrodes classified according to performance are special welding electrodes manufactured according to their special performance, such as ultra-low hydrogen welding electrodes, low dust and low toxicity welding electrodes, vertical downward welding electrodes, lying welding electrodes, bottom-layer welding electrodes, high-efficiency iron powder welding electrodes, moisture-proof welding electrodes, underwater welding electrodes, gravity welding electrodes, etc.

01-16

Precautions for welding stainless steel wood

2023-01-16

Welded stainless steel Welding method of stainless steel 2. Transition layer welding. When welding the transition layer, it is necessary to minimize the melting amount of the base metal and reduce the fusion ratio under the premise of ensuring good fusion. Therefore, a smaller diameter electrode or wire and a smaller wire energy should be used. The thickness of the transition layer should not be less than 2mm. 3. Welding of cladding. When welding the cladding layer, attention should be paid to protect the surface of the cladding layer to prevent welding spatter from damaging the surface of the cladding layer. Arcing, welding scars, rings and temporary supports on the surface of the cladding layer are not allowed. The surface of clad welds shall be as smooth as possible. The butt weld superelevation is not greater than 1.5mm.. Several Methods of Stainless Steel Welding Several methods of welding are as follows: Manual welding (MMA): Manual welding is a very common and easy-to-use welding method. Most welding machines can be TIG welded. In most cases, direct current is used for welding, and the electrode acts both as an arc carrier and as a filler material for the weld. The electrode consists of an alloy or non-alloy metal core wire and a welding rod. The electrode can be either a titanium electrode or a sealed electrode, depending on the thickness and composition. 2. MIG/MAG welding: This is an automatic gas shielded arc welding method. In this method, an electric arc is burned between the current carrier wire and the workpiece under a protective gas shield. The company was founded in, specializing in the processing and production of stainless steel signs. It has many years of experience in stainless steel processing in Qinghai. The products are of fine workmanship and have been praised by customers. The welding process is related to the welding method and other factors. The operation shall be determined according to the material, brand, chemical composition, structure type and welding performance requirements of the welded workpiece. First of all, it is necessary to determine the welding method, such as manual arc welding, submerged arc welding, tungsten argon arc welding, gas shielded welding, etc. There are many types of welding methods and can only be selected according to the specific situation. After determining the welding method, the welding process parameters are formulated. The types of welding process parameters are different. For example, manual arc welding mainly includes: electrode type (or brand), diameter, current, voltage, type of welding power supply, polarity connection, number of welding layers, number of passes, inspection method, etc.

01-14

What are the process requirements for welding brass?

2023-01-14

Welded brass What is the reason why argon arc welding brass has pores? What are the process requirements for argon arc welding brass? 1. The oxide, oil and other dirt on the welding edge of the workpiece and the surface of the welding wire must be removed before welding, otherwise it will cause defects such as pores and slag inclusion, which will reduce the performance of the weld. 2. When argon arc welding brass or bronze, because the melting point of the parent body itself is relatively low, please ensure that the welding of ultra-thin pipe or plate materials can normally form a molten pool. 3, butt joint plate thickness is less than 3mm, do not open groove; When the plate thickness is 3 ~, open 60~70V groove; When the plate thickness is greater than, open 60~70 X groove. In order to avoid incomplete welding, generally do not leave a blunt edge. 4. The workpiece must be preheated before welding. The preheating temperature is ~ ℃ when the plate thickness is less than 3mm; when the plate thickness is more than 3mm, the preheating temperature is ~ ℃. How to Solder Brass with Electric Iron The brass is welded by hot air gun or flame welding. Buy a roll of solder wire with flux and clean the surface of the workpiece. Since the soldering iron head is installed inside the soldering iron core, it is called an external heating electric soldering iron. The soldering iron core is the key component of the electric soldering iron. It is formed by winding the heating wire in parallel on a hollow porcelain tube, the mica sheet in the middle is insulated, and two wires are drawn to connect with the AC power supply. In iron brass, iron precipitates as particles of iron-rich phase, which serves as a nucleus to refine the grains and prevent the growth of recrystallized grains, thereby improving the mechanical and technological properties of the alloy. The iron content in iron brass is usually below 1.5%, its organization is (α + β), has high strength and toughness, has good plasticity at high temperature, and can be deformed under cold state. Heat the electric soldering iron, and when the solder can be melted just now, apply flux, and then apply solder evenly on the soldering iron head to make the soldering iron head eat a layer of tin evenly. Soldering method, the pads and components of the pin with fine sandpaper polished clean, coated with flux. Use the soldering iron head to dip an appropriate amount of solder and contact the solder joint. After all the solder on the solder joint is melted and the component lead head is immersed, the electric soldering iron head is gently raised away from the solder joint along the pin of the component. The welding time should not be too long, otherwise it is easy to burn the components. If necessary, tweezers can be used to clamp the pins to help dissipate heat. After the welding is completed, the residual flux on the circuit board should be cleaned with alcohol to prevent the flux from affecting the normal operation of the circuit after carbonization. The integrated circuit should be finally soldered, and the electric soldering iron should be reliably grounded, or the waste heat should be used for soldering after power failure. Or use a special socket for integrated circuits, solder the socket and then plug the integrated circuit in.

01-13

What are the Welding materials for aluminum?

2023-01-13

What are the thermite welding materials respectively Thermite welding materials, respectively, flux, sand mold, crucible. ① If the wall thickness of the pipe is less than 3.0mm, the wire shall be connected by fixture or brazing; when the pipe is lined or the wall thickness of the pressure pipe is less than, the wire shall not be connected by thermite welding. ② After the surface of the pipe is cleaned, the thickness of the pipe wall shall be measured by ultrasonic method. If the pipe wall thickness is less than 90% of the nominal wall thickness or there are interlayers and pitting pits, no aluminothermic welding shall be performed. Try to weld on horizontal pipes. ③ If the cross-sectional area of the cable exceeds, the cable should be divided into several strands for separate welding, each conductor area does not exceed, to ensure that a welding dose does not exceed, in order to avoid the impact of welding heat on the pipe structure. ④ The distance between the welding position and the circumferential weld is greater than that of the longitudinal weld, so as to avoid welding at the tee or elbow. The spacing between the two welding spots should be greater. The same position can only be welded once. If the first welding fails, the Welding materials shall be cleaned up before the second welding or welding at another position. ⑤ During the implementation of thermite welding, the allowable pressure in the pipe shall be calculated according to the following formula. Pp = 2S(T-1.59) x. In the formula, Pp-allowable pressure in the pipe during welding, MPa. Minimum yield stress of S pipe material, MPa. D Nominal outer diameter of pipe, mm. What is the material of the welding of aluminum alloy? This is the basic formation of argon arc welding. It is a re-casting process. After the molten pool is formed in the parent body, the welding wire is added, so the main component should be the material composition of the welding wire, and there is a little parent body molten material.