An economical plastic mold steel plate and its manufacturing method

Abstract

The invention provides an economical plastic mold steel plate and its manufacturing method. The composition of the steel plate is as follows by weight percentage: C: 0.40%-0.50%, Si: 0.40%-0.70%, Mn: 1.10%-1.50%, Cr: 0.60%‑0.80%, Mo: 0.10%‑0.20%, B: 0.001%‑0.0012%, P<0.020%, S<0.015%, the balance is Fe and unavoidable impurities. Manufacturing method: smelting, continuous casting, furnace heating, rolling, cooling, heat treatment, billet start rolling temperature 1080-1150°C, finish rolling temperature 840-910°C; water cooling after rolling, start cooling temperature 750-800°C , reddening temperature is 500-550°C, air-cooled to room temperature after water cooling; after cooling, the steel plate is tempered at 450-600°C, and the holding time is 1.5-2.5min / mm. The invention obtains a plastic mold steel plate with uniform section hardness, the hardness value of which is equivalent to that of the plastic mold steel 3Cr2Mo, and the maximum section hardness difference is within 5HRC.

Description

technical field [0001] The invention belongs to the field of metal material production, and in particular relates to an economical plastic mold steel plate and a manufacturing method. Background technique [0002] Plastic molds are important equipment in the plastic forming process, and the most important material for making plastic molds is plastic mold steel. In recent years, with the rapid development of my country's plastic industry, the demand for plastic mold steel is increasing. At the same time, in order to improve the service life of molds, processing accuracy and the quality of plastic products, the quality requirements for mold steel are getting higher and higher. . Traditional plastic mold steel is mostly supplied in a pre-hardened state, that is, the hot-processed plastic mold steel module is pre-conditioned to make it reach the final hardness range, which can avoid the damage caused by quenching and tempering after the mold is processed. Defects such as deform...

AI Technical Summary

Problems solved by technology

But the disadvantage is that its composition contains 1.7% Cr, which will increase its production cost

But the disadvantage is that its composition contains 2.0% Cr, which also increases its cost

But the disadvantage is that its composition also contains relatively high elements such as Cr and Mo, and the use of normalizing + tempering process will further increase its production cost and prolong the production cycle

But the disadvantage is that the production cycle of the steel plate is extended by die casting, and the maximum difference in cross-sectional hardness reaches 10HRC, which cannot meet the requirements of high-end molds.

[0009] (1) Alloy elements in steel are high, which increases the production cost of plastic mold steel plate

[0010] (2) The production process is complex, prolonging the production cycle of steel plates and increasing production costs

[0011] (3) The maximum difference in hardness of the steel plate section is too large, which cannot meet the requirements of high-end molds

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