CN1103897A - Casting and forging steel ball using rare earth steel as raw material and the prodn. method - Google Patents

Abstract

The said steel ball is mfd. by using the composition composed of C, Cr, Mn, Mo, Si, B, Re and Fe through the process of smelting, refining, mould casting, and die forging. The product has good anti-wear, high impact toughness, low cost, and short prodn. period; one can supply steel balls suitable for users' work condition according to different requirements of users.

Description

Casting and forging steel ball using rare earth steel as raw material and the prodn. method

The present invention relates to a kind of steel work and manufacture method thereof, specifically, is a kind of rare earth steel casting forged steel ball and manufacture method thereof.

The steel ball amount that whole nation electric power, metallurgy, mine, building materials, chemical industry etc. consume in industry year is more than 2,000,000 tons, domestic steel ball commonly used has two big classes at present, one class is a cast iron ball as middle maganese cast iron ball, high-chromium cast-iron ball, low-chromium cast-iron ball, and other cast alloy iron ball, the characteristics of these balls have wear resistance preferably, alloying level content height, cost height, and the impelling strength that has is low, easily broken, the anti-fatigue performance difference that has is easily peeled off; Another kind of is the forged steel ball as plain ball, 45# ball, and low alloyed steel forged ball is as 40Mn, 50Mn, 60Mn and 45Mn2,9SiMnCr, and BShi body steel ball forges ball, and the characteristics of these balls: 1, alloying level is low, and is not wear-resisting; 2, all must rely on steel mill to produce the production that could guarantee steel ball, ordering goods requires in batches greatly, and the production cycle is long, and the supply of material is difficult for guaranteeing; Order goods from steel ball, order goods to steel billet, the production shipping cycle is long, and middle-chain is many, the cost height, the speed that can not adapt to the operation of present market, often can not on-schedule delivery and sale because of production cycle length, the high uncontested ability of cost, the expansion that influence market and product develops, have and cast the better impelling strength of ball but forge ball, characteristics such as not broken.

The object of the present invention is to provide a kind of wear resisting property good, impelling strength height, production cost rare earth steel low, with short production cycle, that adapt to the various batch quantity supply of material of user requirement are cast forged steel ball and manufacture method thereof.

For achieving the above object, the present invention adopts following technical scheme: it selects following component:

1, carbon: carbon is to influence the material property principal element, and carbon content increases, and hardness intensity increases, and plasticity, toughness reduce, good casting property, and forgeability is poor, takes to select different carbon content for use according to the operating mode of abrading-ball, determines that scope exists: in the 0.8-1.4% scope.

2, manganese: form carbide and increase hardness, with the sulphur effect generate manganese sulfide can in and the deleterious effect of sulphur, be chosen at: 1.5-2.5% increases hardening capacity.

3, chromium: chromium forms carbide and increases hardness, and crystal grain thinning increases toughness, determines: 0.8-1.5%.

4, boron, molybdenum: according to adding the hardening capacity that micro-boron can significantly improve steel in the bibliographic reference steel, strengthen crystal boundary, molybdenum energy crystal grain thinning increases toughness.The use of boron+molybdenum, it is remarkable to improve the hardening capacity effect, is to simplify the important element that thermal treatment process obtains desirable tissue and hardness.Molybdenum is selected: 0.2-0.4%; Boron is selected add-on: 0.004-0.008%.

5, rare earth: rare earth has crystal grain thinning, raising toughness, degasification, purifying molten iron, improves the effects such as distribution of carbide.Selected add-on: in the 0.15-0.30% scope.

6, silicon: silicon is intensive China inkization element＞1% form appearance of graphite later on, and＜1% can occur with the form of Fe3C, and Si content increases, and increase fragility makes the toughness reduction.Selected amount: 0.4-0.6%.

7, Fe surplus.

The manufacture method of above-mentioned rare earth steel casting forged steel ball, it comprises following processing step:

(1) adopt electrosmelting of intermediate frequency, during the liquid steel refining, the Control for Kiln Temperature of oxidation period goes out 1550 ℃-1580 ℃ of liquid steel temperatures at 1580 ℃ ± 10 ℃, pours into casting mold through rare earth, boron composite inoculating after handling;

(2) promptly heat and contour forging technique behind the casting mold, between 1050 ℃-1100 ℃ of the Heating temperatures, 1000 ℃-1050 ℃ of initial forging temperatures, 900 ℃-850 ℃ of final forging temperatures, forged hardening.

Above-mentioned casting mold adopts insulated feeder permanent mold casting effect better.

The present invention compared with prior art has following advantage:

1, wear resisting property is good, the impelling strength height, prove through power station, Jiujiang DTM380/830-4 type low speed steel ball mill installation test run(s), consumption of coal steel ball per ton is 119.1 grams, percentage of damage has only 0.1%, be significantly smaller than national standard (＜3%), liner plate there is not negative interaction, the flour extraction rate height can reduce working time, reduces equipment attrition, carry out fall down test through University of Fuzhou's drop machine, height of free fall is 4.2 meters, and test is impacted to peel off heavily for ten thousand times and is with φ 60 abrading-balls, average single ball: 0.38-0.6 gram/ten thousand times.

2, the production cost of steel ball is low, and it is low more than 400 yuan/ton to forge ball than steel alloy production.

3, with short production cycle.

4, adapt to the mode of supplly of the various batch quantity of user, the supply of material from the hundreds of kilogram to the hundreds of ton can both be satisfied.

5, the steel billet that does not rely on steel mill is produced steel ball in the same old way, better than the existing optional material amount of steel mill qualitatively.

The steel ball that 6, can be fit to user's operating mode according to the different working condition supply of user.

The invention will be further described below in conjunction with embodiment:

C 1% Cr 1% Mn 2% Mo 0.3% Si 0.5% B 0.006%, the 1# rare earth of Re(Baotou rare earth one factory) 0.2%, Fe surplus (weight hundred umbers), above-mentioned component is through following processing step:

1, melting: take electrosmelting of intermediate frequency, during the liquid steel refining, adopt 0.125% left and right sides silicon calcium powder to carry out diffusive deoxidation, the aluminium that carries out bulk deoxidation and 0.06% with 0.1% silico-calcium stone carries out deoxidation again, the Control for Kiln Temperature of oxidation period exists: 1580 ℃ ± 10 ℃, go out 1550 ℃-1580 ℃ of liquid steel temperatures, pour into casting mold after handling through rare earth, boron composite inoculating.

2, casting mold: casting mold adopts sand mold casting and insulated feeder permanent mold casting respectively, and specification is φ 100 spherical and φ 50 * 100 clavates.

Metal type heat-insulation rising head molten iron utilization ratio, finished product rate as can be seen from the table, castability is all good, determines to take the forging type casting of metal pattern insulated feeder.

3, forge: through forged steel ball the crystal grain density of material is increased, During crushing of carbides and suspension shape make its uniform distribution, reach the purpose that improves material property.

(1) heats forged equipment: take 1M ³Reflection coal-powder boiler and the die forging of 160T friction press.

(2) heating and contour forging technique: between 1050 ℃-1100 ℃ of the Heating temperatures, 1000 ℃-1050 ℃ of initial forging temperatures are taked the bright and clean ball of light forging → descaling → reforge distortion → reforge die forging balling-up → gently be swaged into through forging 900 ℃-850 ℃ of temperature, forging.

(3) Re Deli: this kind material has increased hardening capacity because of adopting high-carbon and having added alloying elements such as Mn, Cr, Mo, B, selectes the specification of quality that forged hardening technology can satisfy steel ball through testing, and reduces the quenching cost, and it is obvious to improve economic benefit.

Can make steel ball adapt to various working condition to the suitable adjustment in the content formula ratio of above-mentioned component; Rare earth also can adopt the rare earth of other suitable composition.

Claims (3)

1, a kind of rare earth steel casting forged steel ball, it forms (weight hundred umbers) by following composition:

C 0.8-1.4

Cr 0.8-1.5

Mn 1.5-2.5

Mo 0.2-0.4

Si 0.4-0.6

B 0.004-0.008

Re 0.15-0.30

The Fe surplus.

2, the manufacture method of the described rare earth steel forged steel of a kind of claim 1 ball, it comprises following processing step:

(1) adopt electrosmelting of intermediate frequency, during the liquid steel refining, the Control for Kiln Temperature of oxidation period goes out 1550 ℃-1580 ℃ of liquid steel temperatures at 1580 ℃ ± 10 ℃, pours into casting mold through rare earth, boron composite inoculating after handling;

(2) promptly heat and contour forging technique behind the casting mold, between 1050 ℃-1100 ℃ of the Heating temperatures, 1000 ℃-1050 ℃ of initial forging temperatures, 900 ℃-850 ℃ of final forging temperatures, forged hardening.

3, the manufacture method of rare earth steel casting forged steel ball according to claim 2, it is characterized in that: casting mold adopts the insulated feeder permanent mold casting.