A kind of high-carbon high-aluminum steel for drilling locks and its preparation method

Abstract

The invention discloses a high-carbon and high-aluminum steel used for drilling locks and a preparation method thereof, belonging to the technical field of locks. The chemical composition of the high-carbon and high-aluminum steel of the present invention is calculated as: C: 1%-1.5%, Si: 0.3%-0.6%, Mn: 0.2%-0.6%, P: 0.01%-0.04%, S : 0.02%~0.04%, Bi: 0.03%~0.06%, Al: 1.5%~2.5%, N: 0.003%~0.006%, Ti: 0~0.03%, the rest are Fe and inevitable impurities, and the control group Si+Al ≥ 2.4% in the fraction. The preparation process is as follows: smelting and casting into an ingot according to the set chemical composition, forging the ingot into a billet after high temperature homogenization treatment, and the billet is subjected to hot rolling, heat preservation, quenching, tempering and shot blasting to obtain low hardness and uniformity. A ferrite structure in which a large number of 1-10 μm graphite particles are distributed. The preparation method of the high-carbon and high-aluminum steel of the invention conforms to the process conditions of casting and rolling integration, can realize continuous large-scale production, the drilling performance of the product meets the requirements of continuous drilling processing, and can replace the existing HT200 gray cast iron lock body material.

Description

technical field [0001] The invention relates to the technical field of locks, in particular to a high-carbon high-aluminum steel used for drilling locks and a preparation method thereof. Background technique [0002] Padlocks are the oldest and largest family of locks in the world, and other locks are all derived from padlocks. Pujiang County, Zhejiang Province is currently the largest distribution center for the production and sales of padlocks and gourd locks in my country. It produces more than 300,000 tons of padlocks and gourd locks every year. The lock body is mainly divided into stainless steel lock, copper lock, iron lock and zinc alloy lock according to the material. Among them, the iron lock body is the most widely used because of its low price and good drilling performance, so the output is also the largest. [0003] At present, the material of iron lock bodies on the market is mainly HT200 gray cast iron. The main reason is that there are a large number of graph...

AI Technical Summary

Problems solved by technology

Although gray cast iron has excellent drilling performance, but its plasticity and toughness are low, it is difficult to forge and roll. Therefore, induction furnace melting + die casting is mainly used for production. This process not only consumes a lot of electricity, but also has low production efficiency. , causing great environmental pollution

[0004] The national invention patents with publication numbers CN101899555A, CN101906597A, CN106947907A, and CN107904377A obtained a relatively high proportion of graphite particles by optimizing the composition of alloy elements and rolling and heat treatment processes, and successfully prepared graphite free-cutting steel with excellent cutting performance and cold and hot forming performance. However, the hardness of the steel is relatively high and the particle size of the free-cutting phase stone in the steel is small. It still has the characteristics of high resistance, slow chip removal, and rapid temperature rise of the drill bit during high-speed drilling, which cannot meet the continuous requirements of padlocks or gourd locks. It needs further improvement

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