High-hardness high-hardenability pre-hardening plastic mould steel and preparation method thereof

Abstract

The invention discloses a high-hardness high-hardenability pre-hardening plastic mould steel and a preparation method thereof and belongs to the technical field of tool and mould steels. To be specific, the steel comprises, by weight percentage, 0.40-0.50% of C, 0.2-0.5% of Si, less than or equal to 0.030% of S, less than or equal to 0.030% of P, 0.6-1.0% of Mn, 0.8-1.5% of Ni, 0.6-2.0% of Mo, 1.6-2.5% of Cr, 0.1-0.5% of V and the balance Fe and inevitable impurities. The high-hardness high-hardenability pre-hardening plastic mould steel has the beneficial effects that compared with the priorart, the steel is higher in pre-hardening hardness, toughness and hardenability; the comprehensive performance is more excellent; and the steel can be used for producing a high-hardness large-size pre-hardening plastic mould steel module more easily, so that user requirements are met.

Description

technical field [0001] The invention belongs to the technical field of tool and die steel, and in particular relates to a high-hardness and high-hardenability pre-hardened plastic mold steel and a preparation method thereof. The pre-hardened plastic mold steel has high hardness, high hardenability and excellent comprehensive performance. It is suitable for all kinds of large and extra large plastic mold steels with high polishing performance. Background technique [0002] Plastic products are now widely used as substitutes for metal products, and the amount of high-strength engineering plastics, ultra-high-strength engineering plastics, and resins added with a large amount of GF is increasing. With the widespread use of plastic products in industries such as automobiles and home appliances, the size requirements for mold steel used in the manufacture of plastic product molding molds are increasing. At present, the large-scale plastic mold steel widely used in the market is ...

AI Technical Summary

Problems solved by technology

However, when the traditional 3Cr2MnNiMo steel is pre-hardened with high hardness, due to insufficient mechanical properties, especially insufficient impact toughness and hardenability, when producing larger modules (≥800mm thick), cracking, uneven hardness, and poor Difficult to achieve high hardness pre-hardening and other technical problems

like figure 1 As shown, when the pre-hardening hardness of traditional 3Cr2MnNiMo steel is increased from 32 to 36HRC to 38 to 42HRC, due to its own performance characteristics, the tempering temperature should be lowered to below 500°C. It can be seen from the impact toughness curve that in Below 500°C, the impact toughness reaches the lowest value, so cracking and other phenomena will occur, and the requirement of high hardness pre-hardening cannot be achieved

At the same time, the hardenability of 3Cr2MnNiMo steel is insufficient. For the production of modules with a thickness greater than 800mm, it is difficult to harden the core, and it is easy to retain the original pearlite structure, so that its pre-hardening hardness and impact toughness cannot meet the requirements.

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