Cast steel shot with low-carbon martensite structure and preparation process for cast steel shot

Abstract

The invention discloses a cast steel shot with a low-carbon martensite structure and a preparation process for the cast steel shot. The cast steel shot comprises the following chemical elements in percentage by mass: 0.25-0.75% of C, greater than 1.2% and less than or equal to 2.10% of Mn, 0.25-0.50% of Si, greater than 0.05% and less than or equal to 0.10% of P, less than 0.05% of S and the balance Fe, inevitable impurities and alloy elements brought in by raw materials during smelting. In the preparation process, a high-temperature or ultra-high-temperature quenching heating temperature higher than a conventional quenching heating temperature is adopted, and a quenched metallographic structure is the low-carbon martensite structure containing austenite films among laths. The cast steel shot has the advantages of being higher in obdurability, better in use performance, simple in preparation process, high in yield, good in quality and price advantages, environmentally-friendly and wide in application.

Description

technical field [0001] The invention relates to cast steel shots, in particular to a cast steel shot with a low-carbon martensitic structure and a preparation process thereof. Background technique [0002] There are two main methods of preparing shot blasting steel shot and shot blasting steel shot used to clean the surface of metal (casting) parts, improve the surface quality of metal (casting) parts, or strengthen the surface of metal parts: one is to use scrap steel and other raw materials After smelting and refining, the steel shot obtained by granulating high-temperature molten steel with a certain chemical composition by atomization or centrifugal method is called cast steel shot; Steel wire, the steel shot obtained by cutting into sections and subsequent finishing, is called cut wire shot. Among them, the preparation method of cast steel shot has the characteristics of simple preparation process, low cost, small performance deviation, and is especially suitable for m...

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Problems solved by technology

[0004] However, it is very difficult to further increase the service life of the above cast steel shot: when adjusting the chemical composition, especially the carbon content, the strength and toughness of the cast steel shot are a pair of contradictions, that is, when the strength increases, plasticity and The toughness will be reduced, and vice versa, so it is often difficult to take care of both; therefore, how to improve the strength and toughness of cast steel shots at the same time, or to make the strength and toughness of cast steel shots have a reasonable coordination has always been to further improve the use of steel shots. The problem of service life needs to be solved urgently; and, the actual production proves that the carbon content of low-carbon cast steel shot is low, so there must be problems of low hardness and non-wear resistance, and due to the high melting point, the fluidity of molten steel is poor and the shrinkage is large, resulting in Porosity and hollow defects in the steel shot lead to a low shot rate, and it is difficult to crush the large-size cast steel shot that cannot be directly used into cast steel grit, etc.

In addition, although the strength and toughness of the cast steel shot can be improved by adding more precious alloy elements such as Cr, Mo, V and further surface processing and strengthening technology, its service life is also improved; The disadvantages are: while consuming precious metal resources, coupled with the cumbersome preparation process, it will inevitably increase the cost of raw materials and process costs

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