100-260 mm-thick tempering-state prehardened plastic mold steel plate and manufacturing method thereof

Abstract

The invention relates to a 100-260 mm-thick tempering-state prehardened plastic mold steel plate. The steel plate has the following chemical components in percentage by mass: 0.35-0.45 of C, 0.20-0.50 of Si, 0.60-1.00 of Mn, 1.00-2.50 of Cr, 0.20-0.50 of Mo, 0.04-0.15 of V+Ti, 0.01-0.04 of Als, 0.015 or less of P, 0.005 or less of S, and the balance of Fe and inevitable impurities; the steel plate is uniform in performance; the overall hardness difference is not more than 2.0 HRC; and the steel plate reaches NB/T47013.3 plate part I grade requirements by ultrasonic detection. The overall hardness difference is not more than 2.0 HRC; the steel plate reaches NB/T47013.3 plate part I grade requirements by ultrasonic detection; and the total inclusion grade is not higher than 2.5. The chemical components of the mold steel plate are simplified; the improvement is performed from the production process angle; the difference of the steel plate in the thickness direction is reduced; and in particular, the section hardness uniformity is improved.

Description

technical field [0001] The invention belongs to the technical field of heat treatment mold steel plates, and in particular relates to a production process of 100-260 mm thick high-performance quenched and tempered pre-hardened plastic mold steel plates. Background technique [0002] Since entering the 21st century, the rapid expansion of the plastics industry has promoted the development of the domestic mold industry. According to statistics, about 70% of the parts in the electromechanical industry are formed by molds, and more than 80% of the parts in household appliances that use more plastic are Made using moulds. In recent years, plastic products represented by washing machine cylinders, large color TV casings, refrigerator inner cavities, etc. have become more and more large, which has promoted the large-scale development of molds, which directly reflects the thickness requirements of mold steel plates, which are raw materials for molds. . [0003] The performance of ...

AI Technical Summary

Problems solved by technology

Therefore, the pre-hardened alloy die steel plates used in the market are often combined with Cr-Mo or Cr-Ni-Mo alloys. The plastic die steel plates represented by 3Cr2Mo and 3Cr2MnNiMo in GB / T 1299-2014 are normalized. Higher hardness can be achieved under air-cooling conditions after heat treatment, and then tempered at different temperatures to make the steel plate meet the hardness requirements of users, but such alloy matching and heat treatment methods can only meet the production requirements of thin plates and conventional medium-thick plates , when the thickness exceeds a certain range, there will be a large difference in hardness between the surface and the core. For the production of die steel thick plates, it is difficult to improve the performance stability of the core and ensure the uniformity of the performance of the entire plate.

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