Oil quenching heat treating process for low chrome multielement alloy cast balls

Abstract

The invention discloses an oil quenching heat treating process for low chrome multielement alloy cast balls. The main constituents of the low chrome multielement alloy cast balls includes, by weight percentage, C (carbon) 1.5-2.0, Mn (manganese):0.3-1.0, Cr (chromium):2.0-2.8, S (sulphur): <=0.02, P (phosphorus) : <=0.03, and the matrix iron. The heat treating process includes heating as-cast low chrome multielement alloy cast balls to 950-1000 DEG C, subjecting the cast balls to an oil cold treatment after 2-3 hours of heat insulation, when the surface temperature of the as-cast low chrome multielement alloy cast balls is reduced below 250 DEG C, removing the product from an oil pool, stopping the oil cold treatment, subjecting the product to a tempering treatment in a tempering furnace, and subjecting the cast balls to a quenching treatment again after the tempering treatment. The oil quenching heat treating process solves the problem of poor quality in use of the low chrome multielement alloy cast balls in the as cast condition. By means of the oil quenching heat treating process, the products have no cracks; rigidity, toughness and anti-fatigue impact life are increased, consumption is reduced, ball crushing rate is low, a mass of chromium alloy resources are saved and operating cost is reduced for users.

Description

Technical field: [0001] The invention relates to a heat treatment process for quenching chromium alloy cast steel and chromium alloy cast iron, in particular to a low chromium cast ball oil quenching heat treatment process. technical background: [0002] Chromium alloy casting balls and casting segments are a kind of grinding medium widely used in powder engineering such as cement, thermal power, magnetic powder, and mineral processing. Various production enterprises and scientific research units are constantly exploring and developing new processes to reduce consumption during use. Therefore, choosing an appropriate heat treatment process is the key to improving the quality of chromium alloy casting balls and casting segments. [0003] At present, there are three types of chromium-based alloy casting balls and casting sections produced at home and abroad: high-chromium alloy casting balls and casting sections, low-chromium alloy casting balls and casting sections, and low-c...

AI Technical Summary

Problems solved by technology

Chinese patent 200410041736X announced the oil quenching process of high chromium alloy casting balls. The high chromium alloy casting balls and casting segments processed by this process have high hardness, but the product performance is unstable, and the alloy content of high chromium alloy casting balls and casting segments High, high cost, large consumption of chromium resources; low chromium alloy cast balls, low alloy content of casting segments, low cost, but low product hardness, low impact toughness, poor comprehensive mechanical properties, high user cost; low chromium alloy cast balls The cost of the casting section is moderate, but at present, the product is only subjected to a low-temperature tempering treatment at home and abroad, and the as-cast structure cannot be changed, and its comprehensive mechanical properties such as hardness, toughness, and wear resistance are not ideal.

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