steel pipe

    Fracture of high frequency straight seam welded pipe, hydraulic (pneumatic) parts used in the design of mechanical properties, brittle fracture and the use of components related to temperature.     It is found that when the temperature is lower than a certain temperature value, it is found that the data will change into brittle state, the impact absorption work decreased significantly, this phenomenon is called cold brittle, high-strength metal materials occurred in the low stress brittle fracture The organization of the data is far from uniform isotropic tissue will have cracks, there will be inclusions, pores and other defects, these defects can be seen as micro-cracks in the material. Therefore, the design should also be based on the operating temperature of the component to select the appropriate data of the cold and brittle transition temperature.     In general, it is assumed that the data is uniform and continuous isotropic. According to this...

    For the ω (Als ≤ 0.01% straight seam welded pipe, the use of two deoxidizer on the VD treatment of steel in the total oxygen impact is small, can be ω (T.O control in the 20 × 10-6 below; Si-Al-Ba deoxidation After the process can be a lower total oxygen content, the process of deoxidation effect is stronger than Si-Ca deoxidation effect.     When the Si-Ca and Si-Al-Ba two kinds of deoxidizer are used in the high-frequency straight seam welded pipe, the number and size of the inclusions in the smelting process are quite different. The number of inclusions in Si-Al-Ba Less than Si-Ca after deoxidation, and smaller size.     When Si-Ca and Si-Al-Ba are used in the high-frequency straight seam welded pipe, the secondary oxidation of the molten steel occurs during the casting process, but the secondary oxidation of Si-Al-Ba deoxidized molten steel is more serious.     The inclusions in the forging material differ greatly from those in the a...

    Wrong side of high frequency straight seam welded pipe is the most common pre-welding problems, ultra-poor of the wrong side will directly lead to the degradation of steel or scrap. Therefore, pre-welding requires strict control of the amount of wrong side. When the whole root or half of the steel pipe billet error occurs when the general is due to:     1, Open seam adjustment is not in place (seam side);     2, The joint pressure roller adjustment is not in place (pressure roller circumferential angle is not right, or to the tube centerline as the axis, the left and right pressure roller asymmetry, or the relative pressure roller radial extension is inconsistent), no pressure round;     3, The pre-bend is not pre-bending in place, there is a straight edge edge of the phenomenon.     When the head or tail of the tube is wrong, it is generally due to:     1, The import and export roller position is not right; ...

    As the long-distance natural gas pipeline through the long distance, complex geographical environment, therefore, a variety of factors affect the normal pipeline services, but the most important factor can be divided into the external environment and the quality of the pipeline itself. Steel pipe, quality is the most important factor affecting the quality of the tube and the main aspects of the quality of the steel pipe include the use of steel and steel pipe quality steel pipe manufacturing process.     The incomplete fusion of the filled metal base or the filling metal is not filled with metal between the fusions. The main reason for the absence of fusion is when the tank is not clean, the drawing speed is too fast, the welding current is too small, the improper electrode angle, and so on. Slag: refers to the residual residue in the weld metal or non-metallic inclusions. The main reason for the slag is the welding current is too small, the welding speed is to...

    High frequency straight seam welded pipe after welding, the heat treatment is a new elimination of residual stress technology. Before welding, the material is preheated to the post-heat treatment temperature and the weld is continuously heated during the welding process to maintain this temperature. After the welding is completed, it is warmed by the heat-insulating cotton to cool it slowly. This method can effectively reduce the welding residual stress, improve the metal resistance to stress corrosion.     Non-destructive testing of the weld due to the pipeline in the water supply project is a large steel pipe, especially the thickness of t = 30mm steel pipe is used as a pipe bridge, it is necessary to bear the water pressure, but also bear the weight of the steel pipe and water bending moment, so the quality of the welding requirements are particularly high. For the pipe with t = 30mm thick large diameter steel pipe, the longitudinal seam and ring joints are ...

    ERW pipe process in welding machine is used to achieve high-frequency welding of electromechanical systems, high-frequency welding equipment is composed of high-frequency welding machine and pipe forming machine. One high-frequency welding machine generally by the high-frequency generator and feed device composed of two parts, its role is to produce high-frequency current and control it; molding machine by squeezing roller frame, its role is to be high-frequency current. The molten part of the extrusion to eliminate the oxide layer on the surface of the steel and impurities, so that the steel plate completely fused into one.     High-frequency generator     The past, the use of high-frequency welded pipe unit is a three-loop: high-frequency generating units; solid-state inverter; electronic high-frequency oscillator, and later basically improved to a single loop. There are many ways to adjust the output power of high-frequency oscillator, such as a...

    US steel products are with more standards, mainly in the following categories:     ANSI--American National Standard     AISI--American Society of Iron and Steel Standards     ASTM--American Society for Testing and Materials     ASME--American Society of Mechanical Engineers     AMS--Aerospace material specifications (one of the most commonly used materials specifications in the US aviation industry, developed by SAE)     API--American Petroleum Institute standards     AWS--American Welding Association Standard     SAE--American Society of Automotive Engineers Standards     MIL--US military standards     Qq--US federal government standards     API--American Petroleum Institute standards     ANSI--American National Standard     ASME--American Society of Mechanical Engineers     ASTM--American Society for Testi...

    1. ASTM A53 thick-walled seamless steel pipe hot rolling position were from the steel head 38,118m, mainly in the middle of the strip.     2. It is speculated that the gap starts at the middle of the width of the strip, because the rolling force and shear force in the rolling process cause the gap to be stretched to form a macroscopic macropore.     3. Seamless steel pipe in the cold rolling production process interrupted with the fracture surface smooth, no obvious before and after fracture surface defects.     The microstructure of the fracture was observed, and the typical ductile ductile fracture morphology was observed. At the same time, the fracture was layered, the central dimple was larger, the dimple was narrowed near the surface, and the crack appeared the center fracture And the depth of fracture at the center is deep, and it is presumed that the stratified topography is closely related to the central segregation.   ...

    ASTM A179 cold drawn seamless pipe is mainly used in various sectors of the metal structure facilities, mainly after the rust of steel pieces immersed in 440 ~ 460 ℃ melting zinc solution, so that the steel surface attached to the zinc layer, which play a preservative purpose. This is an effective way of metal corrosion, the use of the main features are the following:     (1) ASTM A179 cold drawn seamless pipe manufacturers with thick dense dense zinc layer covered in the cold drawn seamless tube surface, it can avoid cold drawn seamless tube matrix and any contact with the corrosion solution to protect the steel matrix from corrosion. In the general atmosphere, the surface of the zinc layer to form a layer of thin and dense zinc oxide surface, it is difficult to dissolve in water, so the steel matrix plays a protective role. If zinc oxide and other components of the atmosphere produce insoluble zinc salt, the anti-corrosion effect is more desirable.   ...

    In the production process of astm a179 cold drawn seamless pipe, there are cold hardening and hydrogen embrittlement phenomenon, which are caused by cold drawn seamless tube cracking the main reason.     Analysis of the phenomenon of bursting astm a179 cold drawn seamless pipe is a smaller diameter of the seamless steel pipe through the drawing die for cold forming cold forming, the process route is generally annealing, pickling, drawing. Cold-drawn small diameter seamless steel pipe in the drawing process, sometimes from beginning to end like the same as the cracker bamboo crack phenomenon, we call this phenomenon is cracking.     The reasons for cracking are:     Effect of work hardening, the steel pipe produces a large amount of plastic deformation during cold drawing, causing significant lattice distortion, which increases the lattice energy and increases the internal energy of the metal, resulting in uneven internal stress of the m...