A kind of non-quenched and tempered pre-hardened plastic mold steel plate and its preparation process

Abstract

The invention provides a non-tempered and pre-hardened plastic die-steel steel plate and a preparing technology thereof. The steel plate comprises components including, by weight, 0.24%-0.36% of C, 0.18%-0.32% of Si, 1.2%-1.4% of Mn, smaller than or equal to 0.010% of P, smaller than or equal to 0.005% of S, 1.8%-2.1% of Cr, 0.20%-0.42% of Mo, 0.50%-0.80% of Ni and the balance Fe and inevitable impurities. The preparing technology comprises the steps that converter smelting, continuous casting, slab reheating, rolling and tempering are conducted, the slab initial rolling temperature is not lower than 1,100 DEG C, and the finish rolling temperature ranges from 890 DEG C to 930 DEG C; after steel plate rolling, air cooling is conducted to 200-300 DEG C; after air cooling, the steel plate immediately enters a furnace to be subjected to tempering treatment, the tempering temperature ranges from 550 DEG C to 580 DEG C, the temperature rise rate is 1.0-1.4 min / mm, and the complete heat preservation time is 1.5-2.0 min / mm. The section hardness of the steel plate produced through the preparing technology is uniform, the section hardness difference value is only 3 HRC, the ASSAB 718 hardness requirement is completely met, machining performance is good, and the non-tempered and pre-hardened plastic die-steel steel plate can be directly used for moulding machining.

Description

technical field [0001] The invention belongs to the field of metal materials, and in particular relates to a plastic mold steel plate and a preparation process thereof. Background technique [0002] Injection molding provides an efficient and economical production method for mass production of plastic products with complex shapes, smooth surfaces and high dimensional accuracy requirements. In recent years, with the requirements of lightweight automobiles and the vigorous development of industries such as household appliances and electronic communication equipment , Injection molded parts are increasingly used in the automotive industry, home appliances, and communications manufacturing. Due to the long production cycle, large investment, high manufacturing precision and high cost of injection molds, the long-term production operation has made mold manufacturers focus on obtaining longer mold life, that is, "mold risk control". The so-called "mold risk" refers to the risk of...

AI Technical Summary

Problems solved by technology

[0004] When the quenching and tempering process is used, the different cooling rates of different thickness sections of the steel plate lead to uneven hardness, and the temperature difference of the section during the quenching process produces internal stress, which increases the tendency of quenching cracking

In addition, processes such as die casting, forging, controlled rolling and controlled cooling, and off-line heat treatment all have disadvantages such as many production links, long cycle times, low production efficiency, and difficult cost control.

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