High-pressure gas bulging thermoforming die of boron steel pipe

Abstract

The invention relates to a high-pressure gas bulging thermoforming die of a boron steel pipe. The die comprises an upper die base and a lower die base, and is characterized in that an upper die forming insert is mounted on the lower surface of the upper die base; a lower die forming insert is mounted on the upper surface of the lower die base; the lower surface of the upper die forming insert and the upper surface of the lower die forming insert are the forming surface of a workpiece of the boron steel pipe; seal heads are arranged at the two ends of the workpiece of the boron steel pipe respectively; the front ends of the seal heads are in contact with the pipe ends of the workpiece of the boron steel pipe; an axial hydraulic cylinder or an air cylinder is connected to the rear ends of the seal heads; vent holes are formed in the centers of the seal heads; the front ends of the vent holes are communicated with the interior of the workpiece of the boron steel pipe; a high-pressure gas station is connected to the rear ends of the vent holes; cooling passages are arranged at the lower part of the upper die forming insert and the upper part of the lower die forming insert respectively and directly connected with a water pipe or connected with the water pipe through the upper die base and the lower die base. According to the die, the workpiece which has the material mechanical strength of 1,500 MPa and is variable in cross-section shape and circumference can be produced.

Description

technical field [0001] The invention relates to a high-pressure gas bulging thermoforming die for a boron steel pipe, in particular to a die for the inner high-pressure gas bulging and quenching process of a boron steel pipe at high temperature, and belongs to the technical field of heat treatment plastic forming. Background technique [0002] As a series of hot-formed steel pipes, the production process of boron steel pipes is divided into two stages: forming and quenching and cooling. Among them: the forming stage needs to be stamped and formed by a mold at high temperature; The transformation from tensite microstructure to martensite microstructure results in extremely high strength and hardness; depending on the type of boron steel, its strength can reach 500-2000MPa. The chemical composition of common boron steels whose strength reaches 1500MPa after hot forming is shown in Table 1. [0003] Table 1 [0004] C Si mn P S Cr B ...

AI Technical Summary

Problems solved by technology

Due to the limitations of the pipe making process and the mechanical properties of the material itself, the strength of the applied pipe fittings is limited, and the tensile strength is difficult to exceed 1000MPa

[0008] At present, the hot forming of common boron steel pipes is mostly an ordinary hot stamping process. There is no high-pressure medium inside the forming process, and it can only adapt to products with equal cross-section perimeters, and the product shape is very limited.

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