CN111941012B - Preparation method of mud cylinder of hydraulic mud gun - Google Patents

Abstract

The invention belongs to the field of machining, and particularly relates to a preparation method of a mud cylinder of a hydraulic mud gun. The technical scheme of the invention is as follows: a preparation method of a mud cylinder of a hydraulic mud gun comprises the following material components in percentage by mass: 0.35 to 0.45 percent of C, 0.15 to 0.35 percent of Si, 0.40 to 0.80 percent of Mn, 0.70 to 1.20 percent of Cr, 0.30 to 0.50 percent of Ti, 0.20 to 0.33 percent of Mo, 0.33 to 0.50 percent of Nd, and the balance of Fe; the preparation process comprises the following steps: the method comprises the following steps of pipe material manufacturing, blanking, rough turning, quenching and tempering, semi-finish turning, mud hole milling and mud hole returning, deburring, sharp edge blunting, glow nitriding and fine grinding. According to the preparation method of the mud cylinder of the hydraulic mud gun, the special alloy structural steel is selected, and the prepared mud cylinder has high tensile strength and yield strength and long service life by utilizing a special heat treatment mode.

Description

Preparation method of mud cylinder of hydraulic mud gun

Technical Field

The invention belongs to the field of machining, and particularly relates to a preparation method of a mud cylinder of a hydraulic mud gun.

Background

The hydraulic mud gun has the function of rapidly and accurately blocking the taphole after tapping so as to enable the blast furnace to rapidly enter the next cycle of operation. The mud jar is hydraulic pressure mud gun heart part, and the mud jar is long-term in high temperature district work to the cooling of beating water regularly, cold and hot alternation can produce small deformation, aggravate the wearing and tearing of mud jar internal surface, the mud phenomenon appears falling. In case pour serious stemming and extrude in a large number from mud jar and mud stopper gap, lead to stifled indisputable tap hole, the blast furnace will be compelled the decompression to block up the mouth, pour mud more serious person, the big gun head is stifled to be burnt on the furnace gate, and the molten iron flows to burn the track on the track under the stove top from the furnace gate, influences the normal transport of blast furnace iron ladle, causes bigger accident. The preparation of the clay cylinder parts requires new ways.

Disclosure of Invention

The invention provides a method for preparing a mud cylinder of a hydraulic mud gun, which selects special alloy structural steel and utilizes a special heat treatment mode to prepare the mud cylinder with high tensile strength and yield strength and long service life.

The technical scheme of the invention is as follows:

a preparation method of a mud cylinder of a hydraulic mud gun comprises the following material components in percentage by mass: 0.35 to 0.45 percent of C, 0.15 to 0.35 percent of Si, 0.40 to 0.80 percent of Mn, 0.70 to 1.20 percent of Cr, 0.30 to 0.50 percent of Ti, 0.20 to 0.33 percent of Mo, 0.33 to 0.50 percent of Nd, and the balance of Fe; the preparation process comprises the following steps: the method comprises the following steps of pipe material manufacturing, blanking, rough turning, quenching and tempering, semi-finish turning, mud hole milling and mud hole returning, deburring, sharp edge blunting, glow nitriding and fine grinding.

Further, the preparation method of the mud cylinder of the hydraulic mud gun comprises the following specific steps:

(1) manufacturing a pipe material: manufacturing a seamless pipe material according to the mass percentage of the material components;

(2) blanking: taking the specification of a seamless pipe material: phi 610X 70-2200 mm/piece;

(3) rough turning: roughly turning an inner hole and an end face, and reserving 5mm of allowance at a single side; after turning around, roughly turning the outer circle and the end face, and reserving 5mm of allowance on a single side;

(4) quenching and tempering: heating the roughly turned workpiece to 920 ℃, preserving heat for 15min, and rapidly cooling in oil; then, heating to 740 ℃, preserving heat for 120min, and slowly cooling in the air;

(5) semi-finish turning: fixing the middle of the workpiece, semi-finish turning an inner hole, and reserving 0.1-0.2 mm of grinding amount on the single side of the inner hole;

(6) finish turning: finely turning a phi 600mm outer circle to form under the condition of keeping the semi-finely turning clamp to be immobile, and finely turning two end faces to form;

(7) milling a mud loading hole and a mud returning hole: respectively milling a mud filling hole and three mud returning holes;

(8) deburring and sharp edge blunting: removing burrs of the workpiece and blunting the sharp edge;

(9) glow nitriding: performing glow ion nitriding treatment on the inner surface of the workpiece, wherein the nitriding temperature of an ion nitriding furnace is guaranteed to be 480 +/-10 ℃; in order to reduce deformation, the temperature rise speed cannot be too high and is ensured to be between 150 and 250 ℃/h; the heat preservation temperature is stable, the furnace can be taken out after 15 hours, and the depth of a nitriding layer is not less than 0.5 mm;

(10) fine grinding: and the inner hole is finely ground, and the surface roughness meets 1.6 mu m.

The invention has the beneficial effects that:

1. the structure of the alloy steel after quenching and tempering treatment is mainly acicular ferrite and strip martensite; because the acicular ferrite can separate the thin strip martensite to the maximum extent and the ferrite must pass through the martensite when the crack propagates, the ferrite can generate a great amount of plastic deformation before the alloy steel is broken so as to absorb a great amount of energy and further hinder the crack from propagating, thereby improving the mechanical property of the alloy steel.

2. The material used in the invention contains Nd which is combined with C and then distributed among crystal grains, and the material plays roles in refining crystal grains and strengthening mechanical properties.

3. The tensile strength of the mud cylinder reaches 1304Mpa, the yield strength reaches 1151Mpa, the impact energy reaches 150J, and the hardness reaches HRC 55-60.

4. The semi-finish turning and finish turning process adopts a clamping technology, the turning is not performed, the coaxiality tolerance of the inner cylindrical surface of the mud cylinder and the outer cylindrical surfaces of the flanges at the two ends is ensured to reach 0.025mm, the perpendicularity tolerance of the two end surfaces of the mud cylinder and the axis is 0.05mm, the roundness tolerance of the inner cylindrical surface of the mud cylinder is 0.015mm, and the cylindricity tolerance is 0.015mm, so that the product quality is ensured.

Drawings

FIG. 1 is a metallographic structure diagram of a clay cylinder;

FIG. 2 is a schematic diagram of a mud cylinder quenching and tempering heat treatment process curve;

FIG. 3 is a mud cylinder machining process diagram.

Detailed Description

A preparation method of a mud cylinder of a hydraulic mud gun comprises the following material components in percentage by mass: 0.35 to 0.45 percent of C, 0.15 to 0.35 percent of Si, 0.40 to 0.80 percent of Mn, 0.70 to 1.20 percent of Cr, 0.30 to 0.50 percent of Ti, 0.20 to 0.33 percent of Mo, 0.33 to 0.50 percent of Nd, and the balance of Fe; the preparation process comprises the following specific steps:

(1) manufacturing a pipe material: manufacturing a seamless pipe material according to the mass percentage of the material components;

(3) blanking: taking the specification of a seamless pipe material: phi 610X 70-2200 mm/piece;

(3) rough turning: roughly turning an inner hole and an end face, and reserving 5mm of allowance at a single side; after turning around, roughly turning the outer circle and the end face, and reserving 5mm of allowance on a single side;

(4) quenching and tempering: heating the roughly turned workpiece to 920 ℃, preserving heat for 15min, and rapidly cooling in oil; then, heating to 740 ℃, preserving heat for 120min, and slowly cooling in the air; the quenching and tempering heat treatment process curve is shown in figure 2, and the metallographic structure is shown in figure 1;

(5) semi-finish turning: fixing the middle of the workpiece, semi-finish turning an inner hole, and reserving 0.1-0.2 mm of grinding amount on the single side of the inner hole;

(6) finish turning: finely turning a phi 600mm outer circle to form under the condition of keeping the semi-finely turning clamp to be immobile, and finely turning two end faces to form;

(7) milling a mud loading hole and a mud returning hole: respectively milling a mud filling hole and three mud returning holes;

(8) deburring and sharp edge blunting: removing burrs of the workpiece and blunting the sharp edge;

(9) glow nitriding: performing glow ion nitriding treatment on the inner surface of the workpiece, wherein the nitriding temperature of an ion nitriding furnace is guaranteed to be 480 +/-10 ℃; in order to reduce deformation, the temperature rise speed cannot be too high and is ensured to be between 150 and 250 ℃/h; the heat preservation temperature is stable, the furnace can be taken out after 15 hours, and the depth of a nitriding layer is not less than 0.5 mm;

(10) fine grinding: and the inner hole is finely ground, and the surface roughness meets 1.6 mu m.

Claims (1)

1. The preparation method of the mud cylinder of the hydraulic mud gun is characterized in that the used material components are calculated according to the mass percentage: 0.35 to 0.45 percent of C, 0.15 to 0.35 percent of Si, 0.40 to 0.80 percent of Mn, 0.70 to 1.20 percent of Cr, 0.30 to 0.50 percent of Ti, 0.20 to 0.33 percent of Mo, 0.33 to 0.50 percent of Nd, and the balance of Fe; the preparation process comprises the following steps: manufacturing a pipe material, blanking, rough turning, quenching + tempering, semi-finish turning, milling a mud loading hole and a mud returning hole, deburring, blunting sharp edges, performing glow nitriding and fine grinding; the method comprises the following specific steps:

(1) manufacturing a pipe material: manufacturing a seamless pipe material according to the mass percentage of the material components;

blanking: taking the specification of a seamless pipe material: phi 610X 70-2200 mm/piece;

(3) rough turning: roughly turning an inner hole and an end face, and reserving 5mm of allowance at a single side; after turning around, roughly turning the outer circle and the end face, and reserving 5mm of allowance on a single side;

(4) quenching and tempering: heating the roughly turned workpiece to 920 ℃, preserving heat for 15min, and rapidly cooling in oil; then, heating to 740 ℃, preserving heat for 120min, and slowly cooling in the air;

(5) semi-finish turning: fixing the middle of the workpiece, semi-finish turning an inner hole, and reserving 0.1-0.2 mm of grinding amount on the single side of the inner hole;

(6) finish turning: finely turning a phi 600mm outer circle to form under the condition of keeping the semi-finely turning clamp to be immobile, and finely turning two end faces to form;

(7) milling a mud loading hole and a mud returning hole: respectively milling a mud filling hole and three mud returning holes;

(8) deburring and sharp edge blunting: removing burrs of the workpiece and blunting the sharp edge;

(9) glow nitriding: performing glow ion nitriding treatment on the inner surface of the workpiece, wherein the nitriding temperature of an ion nitriding furnace is guaranteed to be 480 +/-10 ℃; in order to reduce deformation, the temperature rise speed cannot be too high and is ensured to be between 150 and 250 ℃/h; the heat preservation temperature is stable, the furnace can be taken out after 15 hours, and the depth of a nitriding layer is not less than 0.5 mm;

(10) fine grinding: and the inner hole is finely ground, and the surface roughness meets 1.6 mu m.

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