The alloy elbow
Alloy bend is a kind of general term of many kinds of elbow, its materials are various, common have carbon steel, manganese steel, nickel steel etc. Alloy bend in the pipe bend as often fitting link prerequisite products are widely used, connect two of the same nominal diameter pipe, make the line do turn 90 °.
The manufacturing standard of alloy elbow is: GB, American standard (ANIS), daily standard (JIS), British standard (BS), German standard (DIN), Italian (UNI), etc.
Alloy elbow points: according to the Angle of 45 ° and 90 ° 180 ° three kinds of commonly used, according to the requirements of the project also included Angle 60 °, and other abnormal alloy elbow; The method can be divided into: pushing, pressing, forging, casting, etc。 (it's generally all forged now。)
The bending head of the alloy can be divided into: pushing, pressing, forging, casting etc。 (it's generally all forged now。)
Alloy elbow is divided by the radius of curvature: it can be divided into long radius elbow and short radius alloy elbow。 The long radius alloy elbow refers to the outer diameter of the tube with a curvature radius of 1。5 times, namely R= 1。5d。 The radius of the radius of the short radius is equal to the diameter of the tube, which is R= 1。0d。 (D is the diameter of the alloy bend, R is the radius of curvature)。
Production method of alloy elbow:
1. Hot push forming
Hot push bend forming technology is to use special elbow push system core machine, mold and heating device, to set on the mould of billet in pushing forward movement, under the impetus of the machine in motion is heated and hole enlargement and forming process. Hot push bend deformation characteristics are based on volume before and after plastic deformation rule of metal materials determine the pipe diameter, pipe diameter bend diameter, through the core module and control the deformation of the process, make the inner arc compressed metal flow, the compensation to other parts of the thinned by hole diameter, wall thickness uniform Angle is obtained.
Hot push bend forming technology has a good appearance, uniform wall thickness and continuous operation, suitable for the characteristics of mass production, thus become the main forming methods of carbon steel, alloy steel elbow, and also the application in some of the specifications of the stainless steel elbow forming。
Forming process of the heating mode with intermediate frequency or high frequency induction heating (heating can be multiple times or lap), flame heating and reverberatory furnace heating, adopt what kind of heating mode according to the condition of forming product requirements and energy。
2. Stamping forming
Stamping elbow is applied in batch production of seamless elbow early forming process, the commonly used in the production of the specifications of the elbow has been replaced by a hot method or other forming process, but in some of the specifications of the elbow because of less production quantity and wall thickness too thick or too thin.
The product is still in use when it has special requirements. The punching forming of the elbow adopts the pipe blank equal to the outer diameter of the elbow, and the pressure machine is used to directly suppress the forming in the mould.
Before stamping, the tube billet is placed on the top of the mould, and the inner core and the end mould are put into the tube billet。 The upper mold downward movement starts to suppress, and the bending is formed through the constraint of the external mould and the support of the inner mould。
Compared with the heat push process, the appearance quality of the stamping forming is inferior to the former. In the shape of the punching elbow, the outer arc is stretched and there is no extra metal to compensate for it, so the wall thickness of the outer arc is about 10% less. However, due to the characteristics of single-piece production and low cost, the process of punching elbow is used in the manufacture of small batch and thick wall elbow.
The stamping elbow is divided into cold stamping and hot stamping, which usually chooses cold stamping or hot stamping according to material properties and equipment ability.
Cold extrusion of bend forming process is the use of dedicated elbow forming machine, pipe to be included in the external formwork, upper and lower mould clamping, under the impetus of the push rod, tube billet model along the internal model and reserved clearance sports and forming process。
Using die cold extrusion process inside and outside the elbow and good appearance, uniform wall thickness, size deviation is small, so for the stainless steel elbow especially thin wall stainless steel elbow forming more made by this technology。 The internal and external mode precision of this process is high; The wall thickness deviation of the tube is also more demanding。
Remind you my company alloy elbow problems should be noticed in the process of using, because of considering the safety of using alloy steel elbow, and the service life, should focus on improving pipe lined with toughness, impact resistance, and resistance to wear, make the alloy steel elbow in electric power, mining, metallurgy industry, material conveying, output, are in use at close range, high pressure conveying under considerable pressure.