Hot Forming and Water Cooling Process of Equal Section Boron Steel Pipe

Abstract

The invention relates to a thermal forming and water cooling process of a uniform-section born steel pipe. The process is characterized by comprising the steps of (1) processing the boron steel pipe into a part of which the shape and size are basically similar to the final workpiece; (2) heating the boron steel pipe part to reach the temperature of 850 to 950 DEG C through a heating device; (3) conveying the boron steel pipe part into a die of a thermal forming press; (4) closing part of the die part area or completely closing, then moving an axial shaft toward the workpiece, wherein a sealing head is arranged at the front of the axial cylinder to seal two ends of the workpiece; quickly pouring cooling water into the workpiece by the axial cylinder through a water hole in the end part of the sealing head, and circularly cooling the workpiece by the circulating mode of pouring water through one end and draining water through the other end of the sealing head, wherein the pressure of the cooling water is medium and low pressure and is preferably 0.1 to 25MPa; the cooling water is antirust soft water; the temperature is controlled to be 5 to 45 DEG C; (5) releasing pressure and opening the die. With the adoption of the process, the part of which the mechanical strength reaches 1500MPa can be produced.

Description

technical field [0001] The invention relates to a thermal forming and water cooling process of equal-section boron steel pipes, and belongs to the technical field of heat treatment plastic forming and heat treatment. 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 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 [0005] The inte...

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Problems solved by technology

However, the disadvantage of this method is that the middle part of the workpiece, especially the front end of the head, cannot form a tight fit with the mold, so the cooling efficiency in this area is low, and the martensite structure is often unable to form, which becomes a "depression" of product strength

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