Processing technology for welding neck flange

Abstract

The invention discloses a processing technology for a welding neck flange. The processing technology comprises the following processing steps that (1) materials are selected, wherein according to thespecification of the welding neck flange, the specification of an aluminium alloy cast rod is selected, and it is guaranteed that the height-diameter ratio of a blank after feeding is performed is smaller than or equal to 3; (2) a step-shaped blank with the annular cross section is selected; (3) the outer diameter of the neck of a semi-finished product and the outer diameter of the bottom of the semi-finished product reach the pr-determined sizes; (4) the flange blank is continuously gripped into a sealed hole formed by a driving roller and a core roller under the rotation movement effect of the driving roller and the feeding movement effect of the core roller, continuous local plastic deformation is generated, upper and lower press plates limit axial flow of metal, so that the wall thickness of a rolled piece is reduced, the diameter of the rolled piece is increased, and the outline of the cross section of the rolled piece is formed; (5) annealing, rough machining and finish machiningare performed. The obtained welding neck flange has a compact microscopic structure and fined grains, and the mechanical strength, wear resistance and fatigue life of the welding neck flange are obviously superior than those of flanges processed through other forging and machining methods. More importantly, the strict demand of a ring rolling technology for the shape of the blank is reduced.

Description

technical field [0001] The invention relates to the field of flange processing, in particular to a high neck flange processing technology. Background technique [0002] The high neck flange is the core component of the pipeline connection in the fields of petroleum, chemical industry, urban water supply system, and power transmission system. Once it fails, it will lead to leakage accidents and cause serious consequences. Because the neck of the high-neck flange is high and thin, and the difference between the upper and lower sections is large, it brings certain difficulties to its forming. At present, the commonly used production methods are sand casting, forging and welding. The material utilization rate of the casting method is only 50% to 60%, and forming defects such as shrinkage cavity and looseness are easy to occur inside the casting, which affects the service life of the high neck flange. and safety; the quality of the high neck flange formed by forging is better, b...

AI Technical Summary

Problems solved by technology

At present, the commonly used production methods are sand casting, forging and welding. The material utilization rate of the casting method is only 50% to 60%, and forming defects such as shrinkage cavity and looseness are easy to occur inside the casting, which affects the service life of the high neck flange. and safety; the quality of the high neck flange formed by forging is better, but there are disadvantages such as many production processes, high energy consumption, low production efficiency, and large machining allowance.

In addition, there is also a method of ring rolling. Although ring rolling has the advantages of high efficiency and material saving, because the neck of the high neck flange is high and thin, and ring rolling has high requirements for the billet, the billet needs to be Pre-forging is a complex shape such as special-shaped cross-section. In actual production, the trial and error method is often used to obtain the rolling blank. During the rolling process, the end face is prone to forming defects such as fishtails.