Low-cost plastic mold steel with uniform hardness in cross section direction and production method of low-cost plastic mold steel

Abstract

The invention relates to low-cost plastic mold steel with uniform hardness in a cross section direction and a production method of the low-cost plastic mold steel. The steel comprises the following chemical components in percentage by mass: 0.40-0.50% of C, 0.70-1.00% of Si, 1.60-2.00% of Mn, less than or equal to 0.015% of P, less than or equal to 0.005% of S, 0.80-1.00% of Cr, 0.010-0.050% of Als, 0.010-0.030% of Ti, 0.0010-0.0020% of B, 0.0030-0.0080% of N and the balance of Fe and inevitable impurities. Meanwhile, the chemical components further need to meet the formula: B= -0.001507 + 0.0455Als + 0.0318Ti + 0.171N. According to the steel, precious metal elements such as Mo and Cu are not added, only vacuum treatment is adopted for refining molten steel, the rolling process is not limited, through the production process path of stacking cooling and tempering after rolling, normalizing heat treatment generally adopted by the plastic mold steel after rolling is omitted, so that the plastic mold steel is produced at low cost; and the steel disclosed by the invention is high in hardenability, uniform in hardness distribution along the cross section, and suitable for manufacturing plastic molds which have strict requirements on dimensional accuracy, surface roughness and the like and have complex cavities.

Description

technical field [0001] The invention relates to the technical field of mold steel manufacturing, in particular to a low-cost plastic mold steel with uniform hardness in the cross-section direction and a production method thereof. Background technique [0002] Mold is an important basic process equipment in the manufacturing industry. It is widely used because of its high production efficiency, good product quality, low material consumption and low production cost. It is a modern industry, especially for automobiles, motorcycles, aviation, instruments, instruments, medical Equipment, electronic communication, weapons, household appliances, hardware tools, daily necessities and other essential process equipment in industrial fields. Its high degree of industrial relevance is one of the important guarantees for the industrial upgrading and technological progress of various related industries in the manufacturing industry. The level of mold manufacturing has become an important ...

AI Technical Summary

Problems solved by technology

The disadvantage of this application is that the precious metal Mo needs to be added, which increases the production cost; the use of LF and RH refining outside the furnace prolongs the production time and also increases the production cost; the steel plate with 0.40-0.50% C is cooled by spraying water after rolling up to room temperature, increasing the risk of plate cracking

The disadvantage of this application is that the use of LF and RH refining outside the furnace prolongs the production time and increases the production cost; it requires hot delivery and warm loading of the slab, which increases the difficulty of production organization; after rolling the steel plate with 0.32-0.40%C Spraying water to cool down to the red temperature is less than 500°C, which increases the risk of cracking of the steel plate

The disadvantage of this application is that the precious metal Mo needs to be added, which increases the production cost; the heating time of hot-feeding and hot-charging slab into the furnace is 6 hours, which increases the production time in the furnace, increases the cost of fuel and process, and also occupies production capacity; in terms of performance As far as the case is concerned, the difference in hardness of the same section is 2HRC, which is not the same concept as the uniformity of hardness in the direction of the section.

The disadvantage of this document is that it needs to add precious metal Mo, which increases the production cost; the use of LF and RH refining outside the furnace prolongs the production time and increases the production cost

Publication "Study on heat treatment process and hardness of air-cooled economical P20 plastic mold steel" (Zhang Yilin. Research on heat treatment process and hardness of air-cooled economical P20 plastic mold steel [J]. Southern Metal, 2013 (194), 10:18- 20.) Although it is a pilot project, it needs to add precious metal Mo, which will increase the production cost

Images