Cooling gas direct cooling process and device for hot forming die based on boron steel pipe

Abstract

The invention belongs to the technical field of heat treatment plastic forming, and discloses a cooling gas direct-cooling process and device of a hot forming die based on a boron steel tube. According to the method, the corresponding position in the hot forming die can be divided into a convex angle area, a concave angle area and a plane area placed in an upper die and a concave angle area and a plane area placed in a lower die according to each circular arc part apart from linear portions in the geometrical characteristic of the cross section of a product to be shaped; then, the boron steel tube is heated in heating equipment until Austenitizing is reached, the boron steel tube is placed in the hot forming die, and forming processing is conducted on the boron steel tube under the effect of a press machine within the range of 450-850 DEG C; finally, the closed state of the hot forming die is maintained, meanwhile, cooling gas is conveyed into half-opened cooling air passages, so that the cooling gas in the half-opened cooling air passages flows and cools a workpiece directly, and the cooling gas is directly injected into the atmosphere or is recycled through a cooling gas loop ultimately. The cooling gas direct-cooling process and device of the hot forming die based on the boron steel tube not only can make the workpiece be formed smoothly through the way of die stamping in a forming stage, but also can directly cool the workpiece by the cooling gas in a pressure maintaining cooling stage.

Description

technical field [0001] The invention relates to a method and equipment in the technical field of heat treatment plastic forming, in particular to a cooling gas direct cooling process and device for a thermoforming mold based on a boron steel pipe. Background technique [0002] As a series of hot-formed steel pipes, boron steel pipes are produced in the following ways: figure 1 As shown, it is divided into two stages: forming and quenching and cooling, in which: the forming stage needs to be stamped and formed by a mold at high temperature; The transformation of the structure 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 steel with a strength of 1500MPa after hot forming is: [0003] C Si mn P S Cr B min 0.20 0.20 1.00 - - 0.15 0.0015 max 0.25 0.35 1.30 0.025 0.015 0.25 0.0050 [0004] At present, the common ...

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Problems solved by technology

However, this technology enters the pressure-holding and cooling stage after being stamped and formed by the die. First, the heat is transferred to the die steel, and the die steel transfers the heat to the cooling water arranged in it, so as to realize the cooling of the boron steel workpiece; this way the workpiece The cooling efficiency not only depends on the arrangement of the cooling water circuit, but also is limited by the heat transfer efficiency of the die steel. It belongs to the hot forming process of cooling the workpiece indirectly by the coolant.

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