CN101618448A - Process for producing chromium alloy cast steel shots - Google Patents

Abstract

The invention relates to a process for producing chromium alloy cast steel shots, which belongs to the technical field of the manufacturing process of metal particles. The invention mainly provides a process for producing chromium alloy cast steel shots by using leftover bits and pieces of bearing steel. The process for producing chromium alloy cast steel shots is mainly characterized by comprising the following steps: (1) adding 50-70% of bearing steel and 30-50% of low carbon steel into an intermediate frequency furnace for melting, and adding manganese and silicon 10-5 minutes before furnace discharge, wherein the content of the manganese is lower than or equal to 1%, the content of the silicon is lower than or equal to 1%, and the temperature is between 1680 DEG C and 1700 DEG C; then forming the steel shots by centrifugal casting after furnace discharge; (2) baking the steel shots to remove moisture; (3) putting the steel shots into a vibration sieve to be roughly sorted; (4) tempering the steel shots; (5) putting the steel shots into the vibration sieve to be separated, sorted and collected respectively; and (6) selecting the steel shots by air separation, and blowing off hollow shots and malformed shots. The invention has the advantages of stronger hardenability, high hardness and good wear resistance, and the process is mainly used for producing chromium alloy cast steel shots by using bearing steel in particular leftover bits and pieces of the bearing steel generated when producing bearings as raw materials.

Description

Process for producing chromium alloy cast steel shots

Technical field

The invention belongs to the manufacture craft technical field of metallic particles.Be specifically related to a kind of process for producing chromium alloy cast steel shots that is used for abrasive material.

Background technology

The method that existing shot is manufactured be with steel scrap after intermediate frequency furnace melting, fusing, add alloying element, reach desired chemical composition (carbon: 0.85-1.2; Manganese: 0.6-1.1; Silicon: 0.4-1.0; P≤0.04; S≤0.04), temperature is heated to 1500-1550 ℃, molten steel is injected in the casting machine of rotation, and through action of centrifugal force, molten steel dished out falls into the water natural moulding.Bearing steel can produce a large amount of leftover bits in Production of bearing, though these bearing steel leftover bits have the phosphorus content height, contain the characteristics of Cr, have stronger quenching degree simultaneously, hardness height, wearability are good, are made into the speed and the efficient that can improve Treatment of Metal Surface behind the shot.Bad phenomenon such as but as if being raw material with the bearing steel leftover bits, the existing shot production method of employing is produced the Cr alloy balls, and is then poor because of fusing point height, the flowability of Cr, can cause the shot poor surface smoothness, and lopsided ball is many, fragility is big.

Summary of the invention

Purpose of the present invention is exactly that to provide a kind of be the technology that raw material is produced the evanohm cast steel ball at above-mentioned weak point with the bearing steel leftover bits.

Technical solution of the present invention is: a kind of process for producing chromium alloy cast steel shots is characterized in that adopting following processing step to make:

(1), elder generation adds the bearing steel of 50-70% in the intermediate frequency furnace, the mild steel that adds 30-50% again, the manganese of fusing back adding≤1% in 10-5 minute coming out of the stove before ,≤1% silicon, melting is heated to 1680-1700 ℃, after coming out of the stove molten steel is poured in the casting machine, through centrifugal casting forming, obtain shot not of uniform size;

(2), with the shot of smelting and pouring moulding, after pulling out from the pond, the drying stove removes out moisture, bake out temperature is 400-500 ℃;

(3), the oven dry after shot put into vibratory sieve, rough segmentation becomes 0.1-0.8,0.8-1.4,1.4-2.0,2.0-2.8 four classes;

(4), the shot after the rough segmentation put into back-fire arrangement carry out temper, temperature is between 600-650 ℃, tempering time was at 12-25 minute;

(5), the shot after the tempering by different classes of, put into vibratory sieve carry out sorting, respectively receive long-pending, thereby obtain the different finished product shot of model;

(6), the shot after the segmentation is put into hair-dryer and carried out selection by winnowing, the hollow ball that does not reach quality requirement, lopsided ball blows off through the effect of wind-force, obtains the shot of qualified requirement.

The present invention is owing to add the mild steel of 30-50% in the bearing steel of 50-70%, and before coming out of the stove, added in 10-5 minute≤1% manganese ,≤1% silicon, melting is heated to 1680-1700 ℃, after centrifugal casting forming is made shot, carry out again temperature between 600-650 ℃, tempering time is 12-25 minute temper, thereby overcome Cr steel alloy fusing point height, mobile poor, cause bad phenomenon such as shot poor surface smoothness, lopsided ball is many, fragility is big.The present invention utilizes and produces the leftover bits bearing steel (as GCr15) that bearing produces, the Cr steel alloy shot that comes out according to this explained hereafter, on the basis of existing shot composition, increased the Cr element, thereby have stronger quenching degree, hardness height and the good advantage of wearability, thereby the speed in the Treatment of Metal Surface process, efficient have been guaranteed, reduce cost, improved product quality.Simultaneously, the bearing steel leftover bits are turned waste into wealth, reached reasonable resources and utilized the present invention.It is the technology that raw material is produced the evanohm cast steel ball with the bearing steel leftover bits of producing the bearing remainder particularly that the present invention is mainly used in bearing steel.

The specific embodiment

One, in 1.5 tons of intermediate frequency furnace of GCr15 bearing steel leftover bits adding of 900 kilograms, the mild steel that adds 600 kilograms again, be heated to 1680-1700 ℃ of melting, fusing back 10-5 minute elder generation before coming out of the stove adds 15 kilograms of manganese, adds 15 kilograms of silicon again, come out of the stove, pour tundish into, by overhead traveling crane is transported to casting machine, molten steel is poured in the casting machine, through centrifugal casting forming, obtain shot not of uniform size.

Two, the shot of smelting and pouring moulding is pulled out from the pond after, put into temperature and be 400-500 ℃ heating furnace oven dry and remove out moisture.

Three, the shot after the oven dry is put into six layers of vibratory sieve vibrosieve, it is that a class, 0.8-1.4 are that a class, 1.4-2.0 are that a class, 2.0-2.8 are a class that rough segmentation becomes 0.1-0.8.

Four, the shot after the rough segmentation is put into back-fire arrangement, temperature is between 600-650 ℃, according to different classes of, tempering time was carried out temper at 12-25 minute, thereby reduced the hardness of shot, eliminate the internal stress of quenching and producing, guarantee the toughness and the wearability of shot.0.1-0.8 class is-minute; 0.8--1.4 class is-minute; 1.4-2.0 class is-minute; 2.0-2.8 class is-minute.

Five, the shot after the tempering by different classes of, put into vibratory sieve segment sorting, respectively receive long-pending, thereby obtain the different finished product shot of model.

Six, the shot after the segmentation is put into hair-dryer and carry out selection by winnowing, the hollow ball that does not reach quality requirement, lopsided ball blows off through the effect of wind-force, obtains the shot of qualified requirement.

Seven, qualified finished product shot is packed, weighs, puts in storage.

The key technical indexes of product of the present invention:

Chemical analysis/title	Cast steel ball
		Carbon (C)	??0.85-1.00％
Manganese (Mn)	??0.60-1.00％
		Silicon (Si)	??0.40-0.80％
Chromium (Cr)	??0.60-1.00％
		Sulphur (S)	Less than 0.04%
Phosphorus (P)	Less than 0.04%
		Hardness (HRC)	??40-50
Metallographic structure	The tempered martensite of homogeneous
		Carbide	Smaller or equal to secondary
Density	??≥7.2g/cm 3

Claims (1)

1, a kind of process for producing chromium alloy cast steel shots is characterized in that adopting following processing step to make:

(1), elder generation adds the bearing steel of 50-70% in the intermediate frequency furnace, the mild steel that adds 30-50% again, the manganese of fusing back adding≤1% in 10-5 minute coming out of the stove before ,≤1% silicon, melting is heated to 1680-1700 ℃, after coming out of the stove molten steel is poured in the casting machine, through centrifugal casting forming, obtain shot not of uniform size;

(2), with the shot of smelting and pouring moulding, after pulling out from the pond, the drying stove removes out moisture, bake out temperature is 400-500 ℃;

(3), the oven dry after shot put into vibratory sieve, rough segmentation becomes 0.1-0.8,0.8-1.4,1.4-2.0,2.0-2.8 four classes;

(4), the shot after the rough segmentation put into back-fire arrangement carry out temper, temperature is between 600-650 ℃, tempering time was at 12-25 minute;

(5), the shot after the tempering by different classes of, put into vibratory sieve carry out sorting, respectively receive long-pending, thereby obtain the different finished product shot of model;

(6), the shot after the segmentation is put into hair-dryer and carried out selection by winnowing, the hollow ball that does not reach quality requirement, lopsided ball blows off through the effect of wind-force, obtains the shot of qualified requirement.