CN1055424C

CN1055424C - Iron casting compound roll and its making method

Info

Publication number: CN1055424C
Application number: CN94111491A
Authority: CN
Inventors: 吴树高; 吴侃; 吴弟弟
Original assignee: Individual
Current assignee: Individual
Priority date: 1994-11-04
Filing date: 1994-11-04
Publication date: 2000-08-16
Anticipated expiration: 2014-11-04
Also published as: CN1105612A

Abstract

The present invention relates to an iron casting compound roll which comprises a working layer of a roll body and a roll core, wherein the working layer of the roll body is made from the composition of the following proportion by weight: 3.00 to 3.50% of C, 0.60 to 1.20% of Si, 0.30 to 0.80% of Mn, 3.00 to 4.50% of Ni, 0.60 to 1.50% of Cr and 0.60 to 1.20% of Mo; the roll core of the roll is made from the composition of the following proportion by weight: 3.00 to 3.50% of C, 1.50 to 3.00% of Si, 0.30 to 0.80% of Mn, at most 0.50% of Cr, at most 1.00% of Ni and at most 0.50% of Mo. The casting method of the roll comprises: casting the working layer of the roll body centrifugally; casting the roll core in mould assembling; cooling the roll in a mould and controlling cooling speed after the temperature of the roll is 700 DEG C; enabling the temperature of the roll to decrease from 700 DEG C to 250 DEG C for more than 15 hours. The working layer of the obtained roll has the advantages of high hardness, uniformity, wear resistance, good resistance to sudden heating, no need of spheroidization, high yield, low cost and long service life.

Description

Cast-iron compound roll and manufacture method thereof

The present invention relates to a kind of cast-iron compound roll and manufacture method thereof.

Cast-iron compound roll and manufacture method thereof, existing at present many, body of roll working lining (skin) much all is an alloy nodular cast iron, and for example Chinese patent 92109644.5 is exactly outer and internal layer all is composite rolls of spheroidal graphite cast-iron, and it has introduced nodulizer, pouring temperature and composition.Spheroidal graphite cast-iron has just increased by one technology and has also just improved cost owing to needs spheroidising, and spheroidizing process often has stability problem.

Task of the present invention is to improve material and technology, proposes a kind of spheroidising of not doing, and appropriate change cast iron and alloy and content propose Heat Treatment technology, improves roll working lining intensity, hardness, wearability and resistance to sudden heating.

Technical scheme of the present invention is:

One, roll: partly synthetic by the body of roll and roller core two, the material of roll is that body of roll working lining is different with the roller core part.

I, body of roll working layer are nickel-chrome-molybdenum alloy cast irons, and composition is: C:3.00～3.50%, Si:0.60～1.20%, Mn:0.30～0.80%, Ni:3.00～4.50%, Cr:0.60～1.50%, Mo:0.60～1.20%

Ii, roller core portion material are that casting pig or low-alloy cast iron composition are: C:3.00～3.50%, and Si:1.50～3.00%, Mn:0.30～0.80%, Cr :≤0.50%, Ni :≤1.00%, Mo :≤0.50%

Iii, body of roll working lining matrix are that bainite, graphite are point, strip.

Two, the roll manufacture method has casting and heat treatment two partly, the casting technique routine, and heat treatment is Heat Treatment technology, about 1400 ℃ of molten iron temperatures, the molding box conventional Temperature is 200 ± 50 ℃;

Casting technique is:

I, with centrifugal casting method cast roll barrel working lining, wait to solidify.

Ii, mould assembling, the cast roller core.

Technology for Heating Processing is a Heat Treatment technology:

Iii, be cooled to 700 ℃ with case.

Iv, control cooling velocity since 700 ℃, make roll from 700 ℃ of temperature fall times that drop to 250 ℃ more than 15 hours.

Technical scheme of the present invention is body of roll working lining or roller core no matter, and the P of its cast iron, S content can meet standard code, also can P :≤0.10%, and S :≤0.06%.

Owing to propose to optimize the nickel-chrome-molybdenum alloy cast iron of proportioning components and new Heat Treatment technical scheme, finished the invention task.

Cast-iron compound roll of the present invention, roller core part material also can be alloy ductile iron or general magnesium iron, its composition can be C:3.00～3.50%, Si:2.00～4.00%, Mn:0.30～0.80%, Cr :≤0.50%, Ni :≤1.00%, Mo :≤0.50%, be nodulizer with Mg, Mg: 〉=0.04%.

Cooling off with case in the Heat Treatment technology in the technical solution of the present invention can be air-cooled, can be that mist is cold, also can be to cool off naturally with case, and 700 ℃ of the temperature of unpacking can have 50 ℃ of following tolerances, and the temperature of promptly unpacking can be 700 ℃～650 ℃.

In the Heat Treatment also can be: unpack at 700 ℃ from 700 ℃ of methods that drop to 250 ℃ control cooling velocity, put into holding furnace, holding furnace control temperature can be 600 ℃, it can be 500 ℃, it can be 400 ℃, can be 300 ℃, make roll in 700 ℃～250 ℃ temperature ranges, keep more than 15 hours.Can reach 20 hours, 30 hours, 40 hours, 50 hours, or the longer time.

The back roll of unpacking can not put into holding furnace, and put into adiabatic good case airtight, naturally cool to 250 ℃ of taking-ups.Because the container good adiabatic function, roll cooling velocity in insulated cabinet can make roll keep more than 15 hours in 700 ℃～250 ℃ temperature ranges extremely slowly.

Embodiment 1, pours into a mould roller core with mould assembling after meeting the nickel chromium triangle molybdenum cast iron centrifugal casting roll barrel working lining of optimizing proportioning components.Air-cooled with case, 690 ℃ of the temperature of unpacking place 600 ℃ of holding furnace insulations to cool to 250 ℃ with the furnace in 20 hours.

Embodiment 2, pour into a mould roller core with mould assembling after meeting the nickel-chrome-molybdenum alloy cast iron centrifugal casting roll barrel working lining of optimizing proportioning, the roller core material is above-mentioned spheroidal graphite cast-iron, S:0.03% wherein, P:0.08%, Mg:0.10%, cold with the case mist, unpack for 680 ℃, unpack the back roll to airtight high heat-insulating material case, 25 hours.

Embodiment 3, pour into a mould roller core with mould assembling after meeting the nickel-chrome-molybdenum alloy cast iron centrifugal casting roll barrel working lining of optimizing the proportioning composition, the roller core material is the alloy inoculation cast iron that meets said ratio, C:3.12%, Si:1.70%, Mn:0.58%, Ni:0.52%, Cr:0.31%, Mo:0.43%, P:0.04%, S:0.02%.Cool off naturally with case the cast back, unpacks to 500 ℃ of holding furnaces, be incubated 16 hours and cool to 250 ℃ with the furnace for 650 ℃.

Embodiment 4, with after meeting the nickel-chrome-molybdenum alloy cast iron centrifugal casting body of roll working lining that is optimized to distribution ratio, and mould assembling cast roller core.Be cooled to 700 ℃ with case and be placed in the airtight better tunnel, with case cooling 30 hours.

The present invention implements the full phase constitution of gained roll working lining matrix and is acicular bainite+point, strip graphite+carbide owing to propose nickel-chrome-molybdenum alloy cast iron and the employing Heat Treatment technology that proportioning components is optimized.The hardness height, HSD can reach 73～83, and the hardness distributing homogeneity is good, and unevenness can reach≤5HSD.Body of roll working lining to roller core has preferably excessively layer, and it is good that wearability and resistance to sudden heating all are.

Because body of roll working lining has saved nodulizer and spheroidizing process without spheroidal graphite cast-iron, the yield rate height, process stabilizing, thus having reduced cost, long service life has better economic.

Claims

1, a kind of cast-iron compound roll, form by roller core part and body of roll working lining two parts, it is characterized in that: body of roll working layer is a nickel-chrome-molybdenum alloy cast iron, the roller core material is nickel chromium triangle molybdenum low-alloy cast iron or general cast iron, body of roll working layer composition is: C:3.00～3.50%, Si:0.60～1.20%, Mn:0.30～0.80%, Ni:3.00～450%, Cr:0.60～1.50%, Mo:0.60～1.20%, the roller core material composition is: C:3.00～350%, Si:1.50～3.00%, Mn:0.30～0.80%, Cr :≤0.50%, Ni :≤1.00%, Mo :≤0.50%.

2, a kind of manufacture method of cast-iron compound roll, with centrifugal casting body of roll working lining, solidify back mould assembling cast roller core, its Technology for Heating Processing of roll after it is characterized in that casting is after being cooled to 700 ℃ with case, roll is controlled cooling velocity after 700 ℃, make roll from 700 ℃ of temperature fall times that drop to 250 ℃ more than 15 hours.

3, by the described cast-iron compound roll of claim 1, it is characterized in that the metallographic structure of roll working lining matrix is acicular bainite+carbide+graphite, graphite is point, strip.

4,, it is characterized in that the S content in the cast iron composition is: S :≤0.06% by the described cast-iron compound roll of claim 1.