Method and device for preparing tube blank by means of differential temperature pushing from equal circular cross section to variable square cross section

Abstract

The invention discloses a method for preparing a tube blank by means of differential temperature pushing from an equal circular cross section to a variable square cross section. The method includes the steps: 1) heating a cylindrical section; 2) pushing a transitional section; 3) pushing the variable square cross section by turning on a linear heating device, keeping the temperature of a flange of the tube blank range from 350 DEG C to 400 DEG C, pushing the tube blank at the speed of 25-30mm / s until forming and then unloading; and 4) turning off an annular heating device and the linear heating device and performing ejection. A device for preparing the tube blank by means of differential temperature pushing from the equal circular cross section to the variable square cross section comprises a heating sleeve, the annular heating device and the linear heating device, wherein the heating sleeve is arranged outside the cylindrical section in a surrounding manner, the annular heating device is arranged on the outer side of the transitional section in a surrounding manner, and the linear heating device extends along a filleted flange of the variable square cross section. By the aid of the method, the tube blank can simultaneously have fine plastic deformation at the flange and better tensile strength on a tension side of a mould, cracking or thinning of the tube blank during pushing can be assuredly avoided, and the quality of the tube blank is improved.

Description

technical field [0001] The invention relates to a method and a device for preparing a tube blank, in particular to a method and a device for preparing a tube blank by differential temperature pushing from a circular section to a variable square section. Background technique [0002] like figure 1 As shown, it is a shell blank from an axially equal circular section to a variable square section manufactured by the pushing method. The shell blank has a large external dimension and belongs to a large variable square section thin-walled shell. The maximum side of the variable square section of the billet can be as long as 1000mm, while the minimum diameter at the circular section is only 300mm, and the overall height is about 1250mm. Viewed from the height direction, the billet can be divided into three parts, the first part is a circular cross section, the third part is a variable square cross section, and the second part is a transition stage between a circular cross section a...

AI Technical Summary

Problems solved by technology

In the existing pushing process, when the blank passes through the rounded corners of the mold to form a flange, a large plastic deformation occurs, and the blank on the side of the mold bears a large tensile stress. Therefore, the existing pushing process has the largest The disadvantage is that the structure and properties of the obtained tube blank workpiece are not uniform: the forming structure and properties of the tube wall are relatively uniform, while the flange is prone to cracks or thinning. This phenomenon occurs when the wall thickness of the workpiece is relatively thin. Chances are high, because it creates a real production hindrance

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