SSAW Pipe

　　We know the quality of the raw materials have a deep influence on the quality of the ERW steel pipe , but how? Below we will discuss how the quality of steel trips influence the quality of ERW steel pipe during the production. 　　1.Why the mechanical properties of the steel trips can affect the quality of ERW steel pipe? 　　For ERW steel pipe, the commonly used steel type is carbon steel. The steel standard and grade includes API 5L GR.B -X70, ASTM A53 GR.A/B/C, ASTM A500 GR.A/B/C etc. 　　If the strip yield point and tensile strength is too high, it will cause difficulties during the steel strip forming. Specially for producing thick wall ERW steel pipe, cracking is easy to happen during pipe welding due to the large resilient materials, large deformation stress. When the tensile strength of steel strips exceeds 635 MPa and elongation less than 10%, cracking can be happen during the welding process. When the tensile strength is less than 300MPa, the strip material in the molding p...

　　During the high frequency welding process, the welding technology, quality control process parameters, the impedance of the induction coil and the position of the placement has significant influence on the ERW steel pipe quality. 　　1. Control the steel pipe weld gap 　　If the weld gap is too much, it might increase the possibility of weld seam cracks. If the weld gas is too small, it will cause weld burning, molten metal splashes due to the excessive heat. It will affecting the quality of welding seam in the end. 　　2. The position of the high frequency induction loop 　　Induction loop should be placed in the same center line with the steel pipe. The distance between induction loop and the squeeeze roll end should be controled close enough without burning squeeze rollers premise. If the induction loop from the squeeze roll farther, the effective heating time will be longer and the heat affected zone will be wider. This will cause the strength of the steel pipe weld penetration ...

　　Residual magnetism causes and impact on quality of welding 　　When the gas pipeline construction and repair welding operations, sometimes magnetic blow phenomena affect the welding process. Forming a magnetic blow is the result of the presence of residual magnetism in the pipe metal. Typically, the magnetic induction and magnetic remanence divided into two processes. Magnetic induction in plants often produce tube links, such as: metal smelting, using electromagnetic crane for loading and unloading, pipe parked or garaged in a strong magnetic field, the magnetization is completed nondestructive inspection method, the pipe is placed close to power lines and so strong. Processes often produce magnetic welding operations during the assembly and the use of a magnetic holder, fixture and took DC welding pipes, such as: prolonged contact is connected to a DC power supply electric wire, bare wire segment or short-circuit pipe welding clamp and so on. 　　When welding with magnetic steel, o...

　　Steel pipe have a hollow section, and the length of which is much larger than the diameter or circumference. So, what steel pipe, from welded type like ERW steel pipe to seamless steel tube, can do for us? 　　Please don’t look down upon these steels, not only are steel pipes used to transport fluids and powdery solids, exchange heat energy, and make mechanical parts and containers, it is also an economical steel. 　　Steel pipe is hiding in our daily li ves, we just don’t find it clearly. For example, your shoe rack, the knife you use for cooking, the tools you use for cooking. Your car, the road you go to work...there are too many and there are countless. 　　There is no doubt that we could not live well without steels. I am no even being joking! That’s all true! 　　The use of steel pipe to manufacture construction structure grid frame, prop and mechanical support can reduce the light weight, save the metal 20 / 40, and realize the mechanization of industrial construction. Making ...

　　Today, Prime Steel will discuss about the key difference between Seamless and ERW Stainless Steel Pipe 　　What is the Raw material required for manufacturing Seamless & ERW Stainless steel Pipes? 　　 Seamless Steel Pipe is made from a solid round steel ‘billet’ which is heated and pushed or pulled over a form until the steel is shaped into a hollow tube. 　　What is the Difference Between Seamless and ERW Stainless Steel Pipes? 　　Electric Resistance Welding (ERW) pipe is manufactured by rolling metal and then welding it longitudinally across its length. Seamless pipe is manufactured by extruding the metal to the desired length; therefore ERW pipe have a welded joint in its cross-section, while seamless pipe does not have any joint in its cross-section through-out its length. 　　In Seamless pipe, there are no welding or joints and is manufactured from solid round billets. The seamless pipe is finished to dimensional and wall thickness specifications in sizes from 1/8 inch to...

　　 Welded pipe is a common seen pipe which usually be used on fluid conveyance. Generally, it is defined to as the large diameter solder pipe, in accordance with the welding as a way for tube, the solder steel pipe consist spiral pipe and straight seam welding tube. 　　Based on the application, it can be divided into general welded pipe, galvanized welded tube, oxygen blowing metric pipe, welded tubes, wire casing, roller tube, deep well pump tubes, auto tube, transformer, electric soldering thin wall pipe, welded pipe and spiral welded tube. 　　Spiral welded pipe is the low carbon structural steel and low alloy structural steel strip according to certain helix Angle rolled into a tube billet, and then solder pipe joints made up, it can use a narrow strip in the production of large diameter steel tube, straight seam solder pipe is hot rolled plate after molding machine molding, roll deformation of steel coil for round cylinder, using frequent current skin effect and proximity effect...

　　(1) When the building of scaffolding outside the building facade along the line erection height is less than 15m, calculated as a single row of scaffolding ; higher than 15m, calculated as a consolidated scaffolding. 　　(2) the upper part of the wall outside the building line chooses 1.5m or more, according to the top of the exterior wall outside the building line or uneven length times the total height of the outer scaffolding erection calculated area; the lower part of the wall in accordance with the vertical part retracts into the envelope projected area calculate according to the appropriate height of a single row of scaffolding itself. 　　(3) lighting recessed portion open well: when mouth width (distance between the exterior structure) ≤3.5m, press the recessed portion exterior wall vertical projection area of a single row of scaffolding, light wells mouth with or without connecting beam are calculated together with the external walls of the integrated scaffolding; when mouth...

　　SUS304 has good corrosion resistance, heat resistance, low temperature strength and mechanical properties, good hot workability such as stamping and bending, no heat treatment and hardening, and no magnetism. Widely used in household goods, tableware, cabinets, indoor pipelines, water heaters, boilers, bathtubs, auto parts, medical equipment, building materials, chemicals, food industry, agriculture, ship parts. 　　SUS316 is particularly resistant to corrosion and high temperature. It can be used under severe conditions, work hardenability and non-magnetic. 　　Suitable for seawater equipment, chemicals, dyes, paper, oxalic acid, fertilizer production equipment, photography, food industry, coastal facilities. 　　SUS316L has better corrosion resistance than SUS316, and has a slightly lower temperature strength. It can be used under severe conditions, work hardenability and non-magnetic. 　　Suitable for seawater equipment, chemicals, dyes, paper, oxalic acid, fertilizer production e...

　　First, preheating 　　Preheating is beneficial to reduce the maximum hardness of the heat affected zone of medium carbon steel and prevent cold cracks. This is the main process measure for welding medium carbon steel. Preheating can also improve joint plasticity and reduce post-weld residual stress. Generally, 35 and 45 steels have a preheating temperature of 150 to 250 ° C or a high carbon content or a large thickness and rigidity. When the crack tends to be large, the preheating temperature can be raised to 250 to 400 ° C. 　　If the weldment is too large and the overall preheating is difficult, local preheating may be performed. The heating range of the local preheating is 150 to 200 mm on both sides of the welded joint. 　　Second, the electrode 　　Basic electrodes are preferred when conditions permit. 　　Third, the groove form 　　Weld the weldment as much as possible into a U-shaped groove for welding. In the case of casting defects, the shape of the groove excavated by the s...

　　Steel pipes can be classified according to rolling processes, whether there are seams, and cross-sectional shapes. According to the rolling process classification, steel pipes can be divided into hot-rolled steel pipes and cold-rolled steel pipes, according to whether there are seams in steel pipes, steel pipes are divided into seamless steel pipes and welded steel pipes, among which commonly used welded steel pipes can be divided into high-frequency welded pipes according to the types of welds. Three kinds of straight seam submerged arc welded pipes and spiral submerged arc welded pipes. The advantages and disadvantages of various types of steel pipes are: 　　 1, seamless steel pipe 　　The seamless steel pipe has a relatively thick wall thickness and a small diameter. However, the pipe diameter is limited, its application is also limited, and the production cost, especially the production cost of large-diameter seamless steel pipe is relatively high. 　 　2, high frequency welded...