Technological method for hot stamping forming manufacturing of automobile part through medium-thickness boron alloy steel sheet

Abstract

The invention discloses a technological method for hot stamping forming manufacturing of an automobile part through a medium-thickness boron alloy steel sheet. The technological method comprises the steps of billet blanking, billet heating and austenitizing, placing of a hot billet into a die, stamping and in-die quenching, and subsequent treatment of a formed part. The improvement lies in that inthe billet heating and austenitizing step, the sheet is heated until the exterior of the sheet reaches about 930 DEG C or above, the temperature of the interior distant from the surface by 1 mm or above is 810-900 DEG C, the hot billet moved out from a heating furnace is grabbed to be transferred into the die stamping step, the hot billet is controlled to stay in air for 4-6 s, and the temperature when the hot billet is placed in the die is 700-750 DEG C; and in the stamping and in-die pressure maintaining and quenching step, the in-die pressure maintaining time is preferably 30 seconds, thewater temperature in a die water circulation cavity is 8 DEG C, the flow rate is 120 L / min, and the temperature when the formed part is taken out of the die is 100-200 DEG C. The technological methodhas the positive effects that the temperature difference is formed inside and outside the billet, and the difficulty that the cooling effect is poor due to the thick sheet and consequently austenitizing is difficult is overcome; and the design precision of the formed part and the strength of components are ensured.

Description

technical field [0001] The invention belongs to the field of forming, and in particular relates to the manufacture of auto parts by hot stamping forming of medium-thickness plates. Background technique [0002] Hot stamping (Hot stamping / Hot press forming), also known as stamping hardening, is a new technology that has emerged in recent years and is specially used for stamping parts of high-strength steel sheets for automobiles. It is also one of the key technical processes for realizing lightweight production of automobiles. Thermoformed products have almost no rebound after forming, and have high forming precision. The strength of stamping parts made by hot stamping technology can be as high as 1500MPa, and it can better absorb vehicle collision energy, reduce vehicle collision deformation, protect the safety of people in the vehicle to the greatest extent and realize the lightweight of the vehicle body. Therefore, it has attracted widespread attention in the industry and...

AI Technical Summary

Problems solved by technology

Because its interior heats slowly when heated and cools slowly when cooled, it not only leads to long heating time and high energy consumption, but also the slow cooling rate makes it difficult for the metallographic structure to obtain the ideal state of complete martensitization, and it is easy to form iron The body acquires bainite, which deteriorates the mechanical properties of the part

Therefore, there are still technical difficulties in the hot stamping and quenching of thick sheet parts such as commercial vehicle frame beams, longitudinal beams, and reinforced plates, resulting in their application being far less extensive and mature than the stamping technology of thin sheet parts.

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