Changsha Xiangjia Metal Materical Co., Ltd.

 The hardness of  SSAW steel pipe  is the ability of metal materials to resist the indentation of the surface of hard objects. According to the test methods and scope application, hardness can be divided into Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, micro hardness and high temperature hardness. There are three commonly used in steel pipes: Brinell, Rockwell and Vickers hardness. Below we will detailed introduce you Brinell hardness. Brinell hardness (HB) Use a steel ball or cemented carbide ball with a certain diameter and press it into the surface of the sample with the specified test force (F). After the specified holding time, remove the test force and measure the indentation diameter (L ) The Brinell hardness value is the quotient obtained by dividing the test force by the indentation spherical surface area. Expressed in HBS (steel ball), the unit is N/mm2 (MPa, and the calculation formula is in the formula: F--test force pressed into the surface of th

  Galvanized steel pipe  is one of types of galvanized products, and the product is very complicated. If customers do not know galvanized steel pipes well, there will be many problems when buy. Therefore, it is nessary to know basic knowledge and skills of galvanized steel pipe. Pay attention to the following points when buying galvanized steel pipe: 1. Appearance: There are regulations of industry standards on appearance quality requirements, especially in terms of delamination, scarring, cracks, etc. The regulations are specific, and there are also regulations for geometric deviations in the implementation standards, such as Curvature, side width, side thickness, top angle number, theoretical quality and other items have strict regulations, which can be well reflected in appearance, and are also a very effective basis for distinguishing the quality of galvanized steel pipes. 2. Chemical composition discrimination: It is scientific to distinguish by chemical composition, because the c

  SSAW steel pipe  is a spiral seam steel pipe made of steel strip (hot-rolled coil), extruded and formed by automatic double-wire double-sided submerged arc welding. SSAW steel pipe production process: put the strip steel into the welded pipe unit, and the strip steel is gradually rolled up after being squeezed by multiple rollers to form a round tube blank with an open gap. The extrusion amount of the rollers is adjusted to control the weld gap at 1 ~3mm, and make both ends of the welding joint flush. Double-sided submerged arc welding is performed on the weld. SSAW steel pipes will do lots tests before they leave the factory to test the mechanical properties, mechanical properties, yield strength, withstand pressure and tensile strength etc. of the steel pipe Three-layer polyethylene (3PE) is a high-performance anti-corrosion coating, which is the outer wall of steel pipes. It has excellent anti-corrosion, insulation, smooth, dense, hard coating, strong adhesion, salt and alkali re

 The main production process of  large-diameter welded pipe , Plate inspection: After the steel plate used to make large-diameter submerged arc welded pipe enters the production line, the whole plate is firstly inspected by ultrasonic; Edge milling: Double-sided milling is performed on both sides of the steel plate by a milling machine to make it reach the required plate width, plate edge parallelism and groove shape.  Pre-bending: Use a pre-bending machine to pre-bend the edge of the board so that the edge has a curvature that meets the requirements; Forming: On the JCO forming machine, one half of the pre-bent steel plate is stamped repeatedly and pressed into a "J" shape, and then the other half of the steel plate is bent into a "C" shape, finally forming an opening The "O" shape 5. Pre-welding: The formed longitudinally welded steel pipes are joined together and the gas maintenance welding (MAG) is selected for continuous welding. Internal welding: For

  LSAW steel pipe  is a steel pipe whose weld seam is parallel to the longitudinal direction of the steel pipe. Generally divided into metric electric welded steel pipes, electric welded thin-walled pipes, transformer cooling oil pipes, etc. Welded pipes with larger pipe diameters can be produced with narrower billets, and welded pipes with different pipe diameters can be produced under the same billet width, but are comparable Compared with long straight seam pipes, the weld length is increased by 30% and 100% respectively, and the production speed is lower. Next, I want to introduce how to measure the length of a straight seam steel pipe. According to the different processes of the manufacturer, the length of LSAW steel pipe measurement system has a various of measurement methods, are following types: 1. The basic principle of measuring the length of the grating ruler is: two fixed-length grating rulers are set on the outer side of the LSAW steel pipe, the grating rulers at both ends

  ERW steel pipe  adopts the skin effect of high-frequency current to produce high temperature and external force extrusion at both ends of the steel plate in a short time. This is a true electrodeless metal butt. Using hot-rolled coils as raw materials, the wall thickness of ERW steel pipes can be controlled to about ±0.2mm. The end of the steel pipe adopts the American APL standard or GB/T9711.1 standard. The pipe end is cut and the conveying length is fixed. In recent years, in natural gas pipeline network projects and natural gas companies, ERW steel pipes have been widely used as the main steel pipes in urban pipeline networks. At present, ERW high-frequency straight seam steel pipe accounts for 60% of the world’s steel pipe usage With the development of the economy and energy industry, long-distance oil and gas pipelines are an important way to ensure energy. In the anti-corrosion construction process of oil and gas pipelines, the surface treatment of ERW steel pipes is one of th

 At present, the material of  SSAW steel pipe  which widely used on the market is Q235B, It is because Q235B material is affordable and its performance is good for many industries, but in some special industries, high-performance materials such as Q345 and L360 are also used. Q235B SSAW steel pipe Material of SSAW steel pipe include: Q235 A, Q235B, 20#, Q345 (16Mn), L245 (B), L290 (X42), L320 (X46), L360 (X52), L390 (X56), L415 (X60), L450(X65), L485(X70), L555(X80), L290NB/MB(X42N/M), L360NB/MB(X52N/M), L390NB/MB(X56N/M), L415NB/MB(X60N/M) , L450MB(X65), L485MB(X70), L555MB(X80). Q235B is composed of Q+number+quality grade symbol+deoxidation method symbol. Its steel number is prefixed with "Q", which represents the yield point of the steel, and the following number represents the value of the yield point in MPa. For example, Q235 represents a carbon structural steel with a yield point (σs) of 235 MPa. Q345 is a kind of steel material. It is a low-alloy steel, "Q" m

 In the steel pipe standard, according to different application requirements, the tensile properties (tensile strength, yield strength or yield point, elongation), hardness, toughness indicators, and high and low temperature properties required by users are specified. The mechanical properties of large diameter spiral steel pipe are: Hardness index The ability of metal materials to resist the indentation of hard objects on the surface is called hardness. According to different test methods and scope of application, hardness can be divided into Brinell hardness, Rockwell hardness, Vickers hardness, Shore hardness, micro hardness and high temperature hardness. There are three commonly used pipes: Brinell, Rockwell and Vickers hardness. Yield point (σs) For a metal material with a yield phenomenon, the stress at which the sample can continue to elong without increasing the force during the stretching process (maintaining constant) is called the yield point. If the force drops, the upper a

 Insulation steel pipe is a steel pipe that has been processed by heat preservation technology and under the action of different working environments and external media to ensure that the internal temperature and surface temperature of the working steel pipe meet or meet the requirements of use. Composition of insulation steel pipe : 1. Outer-protected steel pipe: protect the insulation layer from groundwater erosion, support the pipe working and withstand an external load, to work in the right way. 2. Anti-corrosion layer: protect the outer steel pipe from corrosive substances and extend the service life of the steel pipe. 3. Drag-reducing layer: to ensure the free movement of the working steel pipe during thermal expansion and contraction. 4. Polyurethane foam layer: to ensure the temperature of the medium, and to ensure that the surface of the outer protective tube maintains normal temperature. 5. Barrier and reflective layer: to ensure that the organic foam material does not enter