Vertical axial extrusion process and device of high-temperature and high-pressure seamless tee joint

Abstract

The invention discloses a technical scheme and a device for forming a seamless tee joint by using a tube through hot extrusion, which are used for producing high-temperature seamless tee joints and high-temperature and high-pressure seamless tee joints for pipelines of the power and petrochemical industries. The technical scheme is mainly characterized in that the specification and the process of raw materials can be integrally optimized and a reasonable flow of the materials in the forming process can be realized by combining three heating number processes of radial extrusion, axial vertical extrusion and supporting tube expanding and using a device (a device for realizing the axial line vertical extrusion and supporting tube expanding on a general vertical press machine) for realizing the process, so that the invention overcomes the defect that the shoulder part is thinned in the forming process by using the traditional radial extrusion method, saves raw materials by 20-30 percent as comparison with the traditional radial extrusion method, avoids the weld and the repair of the inner wall of the shoulder part, and improves the safety. The traditional pipe manufacturing factory realizes the vertical axial extrusion in mold on the general press machine by using the traditional press machine and die without setting a transverse hydraulic cylinder so as to reduce the investment and improve the production efficiency.

Description

technical field [0001] The tee manufactured by the technical solution is a high-pressure, high-temperature and high-pressure seamless tee used for electric power, petroleum, petrochemical and chemical industries through hot extrusion. Background technique [0002] At present, the manufacturing method of high temperature and high pressure tee in most pipe fitting manufacturers in my country is the radial compensation method (the pipe is radially hot extruded by multiple fires), and its disadvantage is that the inner wall of the shoulder is subjected to tensile stress during the pressing process so that the shoulder The thickness tends to be thinner, and the inner wall of the shoulder cannot meet the design thickness. In order to obtain sufficient branch height and shoulder thickness, it can only be compensated by increasing the diameter and thickness of the raw material pipe, and it is impossible to limit the thickening of the main pipe to make the main branch The wall thicknes...

AI Technical Summary

Problems solved by technology

[0002] At present, the manufacturing method of high temperature and high pressure tee in most pipe fitting manufacturers in my country is the radial compensation method (the pipe is radially hot extruded by multiple fires), and its disadvantage is that the inner wall of the shoulder is subjected to tensile stress during the pressing process so that the shoulder The thickness tends to be thinner, and the inner wall of the shoulder cannot meet the design thickness. In order to obtain sufficient branch height and shoulder thickness, it can only be compensated by increasing the diameter and thickness of the raw material pipe, and it is impossible to limit the thickening of the main pipe to make the main branch The wall thickness of the pipe is too large, the machining allowance is large and the cut allowance at both ends is large

Even so, most of the inner walls of the tee shoulders need to be repaired to thicken. The non-destructive testing of this part is difficult to implement and can only rely on the welder's technology, and the safety hazard cannot be eliminated.

Cause following shortcoming like this: 1. material utilization rate is low (material utilization rate 60%), because most of them are expensive imported materials, the cost is high and the waste is large

2. Low efficiency due to multiple fires (7-8 fires are required for thick-walled tees)

3. The shape of the shoulder does not meet the design requirements, and the safety is poor (some repair welding metal thickness is more than 100mm)

The forming quality of this method can meet the design requirements (the thickness of the shoulder is not a problem), but they are all equipped with two horizontal extrusion cylinders (several kilotons) on both sides of the vertical universal press, the equipment is complicated, the investment is large, and the cycle is long. ,high cost

In particular, a small number of domestic manufacturing plants lack overall optimization technology (materials and processes), so that the increase in material utilization rate is not large

However, if most of the manufacturers of the radial compensation method in my country want to transition to this axial extrusion method, firstly, they lack the necessary technology and experience, and secondly, they need to go through long-term experiments and practice to explore, because the materials are expensive, and they will pay a lot. cost, and the long-term application of the radial compensation method makes all molds and accessories manufactured for this method. This reality has caused no breakthrough in technology for a long time

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