Welding voltage because the welding arc is conical, and the welding voltage directly affects the length of the arc. Therefore, with the increase of welding voltage, the arc length increases, the moving range of arc spots expands, the weld pool widens and a wider weld formation will be obtained. If welding is carried out in a horizontal position, it will only change the width of the weld without affecting the edge transition of the weld. However, the external welding of spiral welded pipe is carried out on the slope, and the molten weld metal will flow laterally under the action of gravity. It can be seen that the larger the welding voltage and the wider the weld pool, the more serious the trend of lateral flow of weld metal, * eventually leading to the bias flow of weld metal. Coil products are not only rich in types, but also diversified in processing technology and molding. In most cases, after forming, the next process is to expand the diameter of the welded pipe blank to improve the quality of welded pipe shape. In other words the expanding process has become an important process to ensure the quality of finished pipe in the production of large-diameter straight seam coiled pipe.
Main technical measures for low hardening trend
.The principle of encoder length measurement is to install the encoder on the oil cylinder and roll the large-diameter pipe. The oil cylinder pushes the welded steel pipe to move on the roller table, and the same distance is installed on the series photoelectric switch on the other side. When the oil cylinder pushes the steel pipe and the photoelectric switch at the pipe end the stroke of the oil cylinder can be converted according to the recorded encoder reading and provided by the large-diameter continuous control manufacturer, so as to calculate the length of the steel pipe.
Thick wall coiled pipe is usually higher than dn450. Thick wall coiled pipe is sometimes two welds. Why does this happen mainly because of raw material problems and equipment processing problems? The steel plate with the required width of welded pipe required by the customer is usually not produced by the steel plant, so two plates need to be welded, so the weld will occur. The main problem of thick wall coiled pipe is welding. As long as flaw detection can be carried out, the requirements related to delivery are wider than other products. The detection of thick wall coiled pipe is mainly ultrasonic flaw detector. The longitudinal weld on the same cylindrical part of the coiled pipe shall not be greater than 2. When the coil pipe is butt welded, the corresponding parts shall be flushed to. When the nominal diameter is larger than the inner seal, the bottom seal welding shall be carried out. The surface of the circuit board shall be protected from damage during tube rolling treatment.
.In order to make you better understand the installation method of coiled pipe, the following coiled pipe factory will introduce the installation method of coiled pipe: pipe hoop is used, and raw silk belt, white hemp wire, pipe expander, handle and other tools are used to connect coiled pipe and pipe fittings. This method may need repeated debugging due to the great influence of human factors. In addition when the materials of coiled pipes and pipe fittings are different, due to their different thermal coefficients, leakage may occur when cold and hot water are used alternately.?
First, select the specification and put forward the pipe, such as 90 & deg; Elbow, which can calculate the curvature to calculate the 90 DEG of the long material; Elbow, and then cut with the length as the fixed length.
The thickness of thick wall coiled pipe is generally greater than 20mm, and the outer diameter range is 450-3000mm. The thick wall coiled pipe is rolled under the condition of steel plate heating Welding, forming, rib, defect detection, factory. Sometimes the wall thickness is relatively thick and secondary heating is required. The feature is that the outer diameter tolerance is small Uniform wall thickness.
The wall thickness of general coiled pipe is 20mm and the outer diameter is 450-3000mm. It is made of steel plate by direct rolling, welding and forming. The production process of general thick walled coiled pipe can be divided into cold drawing and hot rolling. The production process of cold rolled seamless steel pipe is generally more complex than hot rolling. Roll sizing test shall be carried out for pipe blank first. If there is no response crack on the surface, the round pipe shall be cut by cutting machine, Cut into blanks about meters in length. However, when entering the annealing process, acid shall be used for annealing, and attention shall be paid to whether a large number of bubbles are generated on the surface. If a large number of bubbles are generated, it indicates that the quality of steel pipe can not meet the response standard. In appearance, the cold-rolled seamless steel pipe is shorter than the hot-rolled seamless steel pipe, and its wall thickness is generally smaller than that of the hot-rolled seamless steel pipe, but the surface is brighter than that of the thick wall seamless steel pipe. There is not too much roughness on the surface, and there are not too many burrs in the diameter. The thick wall coiled pipe is a powerful manufacturer, quotation, honest operation, genuine and of the same quality. The thick wall coiled pipe is available from stock, with complete specifications,. Docking and strengthening. Coil pipe processing time is short and delivery is fast Low cost. The rolling pipe is mainly used for pipes, billboards, columns, etc.
The operation is convenient and the measurement accuracy is within & plusmn; Within 10mm, repetition accuracy ≤ 5mm. How about thick wall coiled pipe?
If the top wall thickness of the pipe is equal to the bottom wall thickness, the formula can also be simplified as: (top inner diameter + bottom inner diameter) * 1 / 2 * 0.02466 * pipe length = weight inspection of conical special-shaped coil. 16Mn thick wall coil adopts advanced technology. Jbq6xvzt52aj5 Shenzhen thick wall coil has good use characteristics and performance in use and can show important value and role. The specific functions and values of 16Mn thick wall coil are as follows: it can coil suitable quantitative and wide steel strip and Shenzhen thick wall coil into parallel coils with required inner diameter and wall thickness; The roller is driven by active stepless speed regulation, with small mandrel deformation, high pressure of Shenzhen thick wall winding pipe, strong winding force of Shenzhen thick wall winding pipe, high power transmission efficiency, good winding strength and flat appearance; With self-locking function, the swing arm can be automatically locked without shaking after angle adjustment; With automatic cutting device, the incision is neat without warping angle, and the cutting length of Shenzhen thick wall coiled pipe is optional and adjustable. To operate by two people. 16Mn thick wall coiled pipe is durable and stable in use. Shenzhen thick wall coiled pipe is easy to operate. According to the safety and health standards, the rolling pipe is committed to producing all kinds of rolling pipes and steel penstocks with circumferential seams and longitudinal rings, and is reformed on the basis of similar specifications and models of traditional rolling equipment. The function of improving the parameters of the rolling and welding steel pipe equipment by 30% fills the gap that the original traditional rolling equipment can not produce. It can produce steel pipes with a diameter of more than 400 and a wall thickness of 8-100mm in Shenzhen. Materials mainly include q23 q34 20#, 16 manganese, 16 manganese capacity, etc. Product executive standard: GB / t50205-200, GB / t3092-2001, chemical industry, natural gas transportation, pile driving and urban water supply, heating, gas supply and other projects. The process of designing brand inspection standard thick wall straight seam coiled pipe is generally rolled. If the diameter required by the customer is particularly large, it is difficult for Shenzhen thick wall coiled pipe like machinery and equipment. Shenzhen thick wall coiled pipe needs to be rolled. After the steel plate is rolled, Shenzhen thick wall coiled pipe will weld two rolled steel pipes, The weld formed by Shenzhen thick wall coiled pipe is also called t-weld. Sometimes, two steel plates need to be rolled and welded for thick wall straight seam steel. D7z3xjb87v21w so two welds may appear in one pipe body, also known as double welds. Thick wall straight seam coiled pipe has a wide range of materials. As long as it is a steel plate that can be ordered in a steel plant, X ahzpdqsqu7 is basically OK. The main problem of the product is the welding quality. The welding quality directly determines the quality of the product. Shenzhen thick wall rolling pipe is the main step in thick wall rolling pipe. Suitable for buildings, bridges, dams
where.After, we should prevent the surface damage of the plate. The parts with serious scars must be grinded to make transition, and the wall thickness of the grinded part shall not be less than the design wall thickness. Steel rolling pipe is an unconventional pipe, and there is no domestic standard at present. Therefore, the inspection is mainly aimed at the thickness and weld quality.
What is the manganese content of straight seam coiled pipe? The material of straight seam coiled pipe and an appropriate amount of manganese 1 can significantly improve the cold brittleness of straight seam steel pipe steel, and do not be too large; 4 manganese has an effect on the removal of harmful element oxygen in steel; 5MN can also be used to synthesize high melting point (about 1600 ℃, which is at high temperature in steel, so it can reduce the harmful effect of sulfur and lead to hot processing of steel. Sulfur cracked & ldquo; Hot crisp & rdquo; The phenomenon has decreased.
The butt joint of coiled pipe (with the same wall thickness) shall not exceed 10% of the wall thickness and not more than 2mm.
Main technical measures for low hardening trend
Price.It has advantages and quality. The weld reinforcement obtained is increased, cold rolling, hot rolling and hot expansion.
The butt joint of coiled pipe (with the same wall thickness) shall not exceed 10% of the wall thickness and not more than 2mm.
.Rolled pipe is divided into straight seam rolled pipe and T-shaped welded pipe. The pipe rolling can meet the market demand for less number and more models of welded pipes. It can be used for pipe pile, column, conveying fluid, pressure vessel, etc. The longitudinal weld of the same barrel section of high pressure and high temperature continuous pipe shall not exceed two courses, forming, butt joint and rebar removal. Coil pipe has the characteristics of short processing time, rapid delivery and low cost. The rolling pipe is mainly used for pipes, billboards, columns, etc.
The main purpose of preheating is to reduce the cooling rate of welded joints and preheat temperature. As can be seen from the table, preheating can reduce the cooling rate, but basically does not affect the time spent at high temperature, which is ideal. Therefore, when welding thick wall coils with hardening trend, the main technical measure to reduce the cooling rate and hardening trend is preheating rather than increasing the line energy. Plasma cutting of thick wall coiled pipe is more effective than gas cutting