Super-hard middle-chrome cast grinding ball and production process thereof

Abstract

The invention discloses a super-hard middle-chrome cast grinding ball which consists of the following chemical ingredients: 1.8-3.0% of carbon, 0.3-1.5% of silicon, 0.2-1.5% of manganese, 7.0-10.0% of chrome, 0.02-0.1% of phosphorus, 0.02-0.1% of sulfur, 0.02-0.1% of copper, 0.02-0.1% of molybdenum, 0.02-0.1% of nickel, 0.02-0.1% of tungsten, 0.1-0.2% of rare earth yttrium and 80.1-87.2% of iron. The rare earth yttrium is adopted for evolution inoculation treatment, so that a carbide is changed in shape and distribution, furthermore a net is broken, and meanwhile crystal grains are refined, the texture is compact and the flexibility is improved. By adopting an oil medium annealing and tempering thermal treatment process, eutectic carbide with martensite with the broken net is obtained, the hardness of the middle-chrome grinding ball is HRC60-69, and the toughness and the abrasion resistance of a high-chrome grinding ball are remarkably improved. On premise that the abrasion resistance and the crushing resistance of the grinding ball are further improved, the content of the noble metal chrome is reduced, and relatively the manufacturing cost of the grinding ball is lowered, and significant social benefits are achieved.

Description

technical field

[0001] The invention relates to a grinding medium, that is, a cast grinding ball and a production process thereof Background technique

[0002] As a grinding medium, grinding balls are widely used in powder engineering in industries such as building materials, cement, mining metallurgy, energy thermal power, non-metal processing, coal water slurry and magnetic materials.

[0003] High chromium casting grinding balls are a new generation of high-efficiency grinding balls developed from ordinary forged steel balls, low and medium chromium casting grinding balls. The chromium content is greater than 10%. The known heat treatment technology is oil quenching and low temperature tempering. Under this condition, high-hardness martensite is formed, which greatly enhances the continuity and strength of the matrix, so the hardness and toughness of the grinding ball are significantly improved. my country's current standards (GB / T17445-2009, JC / T533-2004 and YB / T0...

Examples

Embodiment 1

[0042] To produce 30 mm superhard medium chromium casting grinding balls, the chemical composition of which is as follows:

[0043] Carbon (C): 2.78%, Silicon (Si): 0.61%, Manganese (Mn): 0.46%, Chromium (Cr): 8.15%, Phosphorus (P): 0.052%, Sulfur (S): 0.055%; Copper (CLl): 0.062%, molybdenum (Mo): 0.033%, nickel (Ni): 0.027%, tungsten (W): 0.02%, rare earth yttrium (Y-Re): 0.121%, iron (Fe): 87.43%.

[0044] The manufacturing process of 30mm superhard medium chromium casting grinding ball is as follows:

[0045] First, the steel scrap is melted in an intermediate frequency induction furnace, and the temperature is raised to 1510--1550°C, and then Cr, Cu, Mo, Ni, W alloys are added to achieve the required chemical composition. Then put the rare earth yttrium into the molten iron ladle, melt it with molten iron and let it stand for 7 minutes, so as to degrade and inoculate the molten iron. The treated molten iron uses casting direct-reading spectrometer to measure its chemic...

Embodiment 2

[0047] 40 mm superhard medium chromium casting grinding ball, its chemical composition is as follows:

[0048]Carbon (C): 2.86%, Silicon (Si): 0.78%, Manganese (Mn): 0.46%, Chromium (Cr): 7.5%, Phosphorus (P): 0.052%, Sulfur (S): 0.065%; Copper (CLl): 0.057%, molybdenum (Mo): 0.035%, nickel (Ni): 0.031%, tungsten (W): 0.02%, rare earth yttrium (Y-Re): 0.139%, iron (Fe): 89.53%.

[0049] The manufacturing process of 40mm ultra-high chromium grinding body is as follows:

[0050] First, the steel scrap is melted in an intermediate frequency induction furnace, and the temperature is raised to 1510--1550°C, and then Cr, Cu, Mo, Ni, W alloys are added to achieve the required chemical composition. Then put the rare earth yttrium into the molten iron ladle, melt it with molten iron and let it stand for 7 minutes, so as to degrade and inoculate the molten iron. The treated molten iron uses casting direct-reading spectrometer to measure its chemical element content, and the qualified...

technical field

[0001] The invention relates to a grinding medium, that is, a cast grinding ball and a production process thereof Background technique

[0002] As a grinding medium, grinding balls are widely used in powder engineering in industries such as building materials, cement, mining metallurgy, energy thermal power, non-metal processing, coal water slurry and magnetic materials.

[0003] High chromium casting grinding balls are a new generation of high-efficiency grinding balls developed from ordinary forged steel balls, low and medium chromium casting grinding balls. The chromium content is greater than 10%. The known heat treatment technology is oil quenching and low temperature tempering. Under this condition, high-hardness martensite is formed, which greatly enhances the continuity and strength of the matrix, so the hardness and toughness of the grinding ball are significantly improved. my country's current standards (GB / T17445-2009, JC / T533-2004 and YB / T0...

Examples

Embodiment 1

[0042] To produce 30 mm superhard medium chromium casting grinding balls, the chemical composition of which is as follows:

[0043] Carbon (C): 2.78%, Silicon (Si): 0.61%, Manganese (Mn): 0.46%, Chromium (Cr): 8.15%, Phosphorus (P): 0.052%, Sulfur (S): 0.055%; Copper (CLl): 0.062%, molybdenum (Mo): 0.033%, nickel (Ni): 0.027%, tungsten (W): 0.02%, rare earth yttrium (Y-Re): 0.121%, iron (Fe): 87.43%.

[0044] The manufacturing process of 30mm superhard medium chromium casting grinding ball is as follows:

[0045] First, the steel scrap is melted in an intermediate frequency induction furnace, and the temperature is raised to 1510--1550°C, and then Cr, Cu, Mo, Ni, W alloys are added to achieve the required chemical composition. Then put the rare earth yttrium into the molten iron ladle, melt it with molten iron and let it stand for 7 minutes, so as to degrade and inoculate the molten iron. The treated molten iron uses casting direct-reading spectrometer to measure its chemic...

Embodiment 2

[0047] 40 mm superhard medium chromium casting grinding ball, its chemical composition is as follows:

[0048]Carbon (C): 2.86%, Silicon (Si): 0.78%, Manganese (Mn): 0.46%, Chromium (Cr): 7.5%, Phosphorus (P): 0.052%, Sulfur (S): 0.065%; Copper (CLl): 0.057%, molybdenum (Mo): 0.035%, nickel (Ni): 0.031%, tungsten (W): 0.02%, rare earth yttrium (Y-Re): 0.139%, iron (Fe): 89.53%.

[0049] The manufacturing process of 40mm ultra-high chromium grinding body is as follows:

[0050] First, the steel scrap is melted in an intermediate frequency induction furnace, and the temperature is raised to 1510--1550°C, and then Cr, Cu, Mo, Ni, W alloys are added to achieve the required chemical composition. Then put the rare earth yttrium into the molten iron ladle, melt it with molten iron and let it stand for 7 minutes, so as to degrade and inoculate the molten iron. The treated molten iron uses casting direct-reading spectrometer to measure its chemical element content, and the qualified...