High-toughness plastic die steel and production method thereof

Abstract

The invention relates to the field of steel for dies, in particular to high-toughness plastic die steel and a production method thereof. The die steel comprises the chemical components of, by mass, 0.55-0.75% of C, 2.00-3.50% of Mn, 0.45-0.50% of Mo, 2.00-3.00% of Cr, 0.40-0.60% of Sr, 0.80-1.20% of Ni, 0.02-0.04% of S, 0.20-0.30% of V, 0.004% of Ca and the balance Fe and unavoidable impurities. The production method comprises the following steps of plate blank heating, rolling, steel plate slow cooling, normalizing treatment and tempering heat treatment. By controlling rolling and the normalizing process, crystal particles are greatly refined, the hardness uniformity is high, the impact toughness is high, the free-cutting effect is obvious, the performance is stable, and the toughness ishigh.

Description

technical field [0001] The invention relates to the field of mold steel, in particular to a high-toughness plastic mold steel and a production method thereof. Background technique [0002] At present, with the lightening of automobiles and the enlargement of electrical products, the requirements for the performance of die steel are getting higher and higher. Die steel is required to have excellent machinability, small heat treatment deformation, and good dimensional stability. In order to meet the above requirements, the use of pre-hardened die steel has attracted more and more attention. This steel has high purity, stable performance, uniform hardness distribution, good processability and surface finish. The common thickness specification of the steel plate for making plastic molds is 25-120mm. The plastic molds produced by quenching and tempering heat treatment processes have large hardness fluctuations in the thickness direction and are not easy to cut, and the actual pe...

AI Technical Summary

Problems solved by technology

[0003] The technical problem to be solved by the present invention is to provide a high-toughness plastic mold steel and its production method, which solves the problem that the hardness fluctuation in the thickness direction is large and difficult to cut, and the actual performance is limited to a certain extent.