CN104498813A - Heat-resistant material for hydraulic spanner piston and preparation method thereof - Google Patents

Abstract

The invention discloses a heat-resistant material for a hydraulic spanner piston. The heat-resistant material contains the following chemical element ingredients in percentage by mass: 0.06-0.09% of Zr, 0.02-0.04% of Li, 2.3-2.8% of C, 0.03-0.06% of Ba, 1.25-1.755% of Mn, 0.04-0.08% of Cu, 0.05-0.2% of Nb, 1.5-2.2% of Si, not greater than 0.02% of S, not greater than 0.02% of P and the balance of Fe. Cu and Nb are added in the piston material disclosed by the invention, thereby improving the high-temperature corrosion resistance of a casting and enhancing the strength and heat resistance; the production method disclosed by the invention improves the crack resistance of the casting, improves the hardness and the wear resistance of the surface of the piston, and effectively prolongs the service life of the piston; a nodulizing agent and a nucleating agent in the production method disclosed by the invention are capable of improving the roundness of graphite, effectively improving the mechanical property of the nodular iron casting, and realizing a high tensile strength.

Description

A kind of thermotolerance hydraulic spanner piston material and preparation method thereof

Technical field

The present invention relates to casting technology field, particularly relate to a kind of thermotolerance hydraulic spanner piston material and preparation method thereof.

Background technology

Hydraulic spanner is applied to all trades and professions, and hydraulic spanner forms primarily of three parts, body (being also housing), oil cylinder and drive disk assembly.Oil cylinder piston is the important composition parts of hydraulic spanner, is related to working efficiency and the security of spanner.

Current piston also also exists a lot of problem, also needs the hardness, wear resistance, dimensional stability, pore, yield-point, fatigue resistance, the erosion resistance that improve piston.The performance of piston can be improved by the composition and technique improving foundry goods.

Summary of the invention

The object of the present invention is to provide a kind of thermotolerance hydraulic spanner piston material and preparation method thereof, this piston material high temperature corrosion resistance is good, and intensity and good heat resistance, tensile strength is high.

Technical scheme of the present invention is as follows:

A kind of thermotolerance hydraulic spanner piston material, is characterized in that: the chemical element composition that it contains and mass percent thereof are: Zr0.06-0.09, Li0.02-0.04, C2.3-2.8, Ba0.03-0.06, Mn1.25-1.755, Cu0.04-0.08, Nb 0.05-0.2, Si1.5-2.2, S≤0.02, P≤0.02, all the other are Fe.

The production method of described thermotolerance hydraulic spanner piston material, is characterized in that:

(1) raw material is sent into smelting pot, at 1550-1650 DEG C, after melting, detecting the content of each element in molten iron and adjusting each constituent content to meeting recipe requirements;

(2) nodulizing agent being equivalent to iron liquid weight 2.0-2.2% is poured into the side of dykes and dams in casting ladle, the first nucleating agent being equivalent to iron liquid weight 0.3-0.4% is covered on nodulizing agent equably, pour iron liquid, carry out spheroidizing and first time inoculation, pour residue iron liquid again, the second nucleating agent being equivalent to iron liquid weight 0.25-0.35% pours with stream, completes second time inoculation, cast, obtains ingot casting;

(3) ingot casting is heated to 950-1050 DEG C, insulation 5-6 hour, hardening is cooled to less than 100 DEG C, then ingot casting is heated to 600-700 DEG C, insulation 5-6 hour, then naturally cools to room temperature, carries out machine-shaping;

(4) whole piston is carried out surfaces nitrided process, the nitriding treatment degree of depth >=0.3mm, to obtain final product;

Described nodulizing agent is made up of the raw material of following weight part: Ba1-1.6, Mg10-12, Ca 1-1.5, Si10-13, rare earth 2-3, Fe82-86; Preparation method is; By Ba powder, Mg powder, Ca powder, Si powder, rare earth mixing, add the iron powder of 1/3, in argon atmosphere, be heated to iron powder fusing, stir, build, pulverize, cross 10 mesh sieves, obtain powder; Residue iron powder is added crucible, described powder injection is sent into the central authorities of iron powder, in argon atmosphere, be heated to 1510-1520 DEG C, roll is rolled into the thin slice that thickness is 4-5mm, then be ground into the particle that particle diameter is less than 4mm, to obtain final product;

Described first nucleating agent is made up of the raw material of following weight part: La0.1-0.3, Mg3-4, Ca2-4, Mn1-2, Nb0.4-0.7, Si25-30, Fe71-75; Preparation method is, is mixed by metal-powder, grinds 10-20 minute, to obtain final product in argon atmosphere;

Described first nucleating agent is made up of the raw material of following weight part: Y0.1-0.3, Mg2-3, Ca3-5, Mn2-4, Sr0.5-0.7, Si29-35, Fe71-75; Preparation method is, is mixed by metal-powder, grinds 10-20 minute, to obtain final product in argon atmosphere.

Beneficial effect of the present invention

Inventive piston material with the addition of Cu, Nb, can increase the high temperature corrosion resistance of foundry goods, improves intensity and thermotolerance; Production method of the present invention, add the cracking resistance of foundry goods, add hardness and the abrasion resistance of piston face, effectively extend the work-ing life of piston, nodulizing agent of the present invention and nucleating agent can make the roundness of graphite better, the mechanical property of effective raising nodular iron casting, tensile strength is high.

Embodiment

A kind of thermotolerance hydraulic spanner piston material, the chemical element composition that it contains and mass percent thereof are: Zr0.06-0.09, Li0.02-0.04, C2.3-2.8, Ba0.03-0.06, Mn1.25-1.755, Cu0.04-0.08, Nb 0.05-0.2, Si1.5-2.2, S≤0.02, P≤0.02, all the other are Fe.

The production method of described thermotolerance hydraulic spanner piston material is:

(1) raw material is sent into smelting pot, at 1600 DEG C, after melting, detecting the content of each element in molten iron and adjusting each constituent content to meeting recipe requirements;

(2) nodulizing agent being equivalent to iron liquid weight 2.1% is poured into the side of dykes and dams in casting ladle, the first nucleating agent being equivalent to iron liquid weight 0.3% is covered on nodulizing agent equably, pour iron liquid, carry out spheroidizing and first time inoculation, pour residue iron liquid again, the second nucleating agent being equivalent to iron liquid weight 0.3% pours with stream, completes second time inoculation, cast, obtains ingot casting;

(3) ingot casting is heated to 1000 DEG C, be incubated 5.5 hours, hardening is cooled to 90 DEG C, then ingot casting is heated to 650 DEG C, is incubated 5.5 hours, then naturally cools to room temperature, carry out machine-shaping;

(4) whole piston is carried out surfaces nitrided process, the nitriding treatment degree of depth is 0.35mm, to obtain final product;

Described nodulizing agent is made up of the raw material of following weight part (kilogram): Ba1.3, Mg11, Ca 1.3, Si12, rare earth 2.5, Fe84; Preparation method is; By Ba powder, Mg powder, Ca powder, Si powder, rare earth mixing, add the iron powder of 1/3, in argon atmosphere, be heated to iron powder fusing, stir, build, pulverize, cross 10 mesh sieves, obtain powder; Residue iron powder is added crucible, described powder injection is sent into the central authorities of iron powder, in argon atmosphere, be heated to 1515 DEG C, roll is rolled into the thin slice that thickness is 4mm, then be ground into the particle that particle diameter is less than 4mm, to obtain final product;

Described first nucleating agent is made up of the raw material of following weight part (kilogram): La0.2, Mg3.5, Ca3, Mn1.5, Nb0.5, Si27, Fe73; Preparation method is, is mixed by metal-powder, grinds 15 minutes, to obtain final product in argon atmosphere;

Described first nucleating agent is made up of the raw material of following weight part (kilogram): Y0.2, Mg2.5, Ca4, Mn3, Sr0.6, Si32, Fe73; Preparation method is, is mixed by metal-powder, grinds 15 minutes, to obtain final product in argon atmosphere.

Experimental data:

After tested, tensile strength is 619MPa to the material of this embodiment, and unit elongation is 10.5%, and yield strength is 395MPa, and surface hardness is 181HBW, and toughness is 9.1J/ ㎡.

Claims (2)

1. a thermotolerance hydraulic spanner piston material, is characterized in that: the chemical element composition that it contains and mass percent thereof are: Zr0.06-0.09, Li0.02-0.04, C2.3-2.8, Ba0.03-0.06, Mn1.25-1.755, Cu0.04-0.08, Nb 0.05-0.2, Si1.5-2.2, S≤0.02, P≤0.02, all the other are Fe.

2. the production method of thermotolerance hydraulic spanner piston material according to claim 1, is characterized in that:

(1) raw material is sent into smelting pot, at 1550-1650 DEG C, after melting, detecting the content of each element in molten iron and adjusting each constituent content to meeting recipe requirements;

(2) nodulizing agent being equivalent to iron liquid weight 2.0-2.2% is poured into the side of dykes and dams in casting ladle, the first nucleating agent being equivalent to iron liquid weight 0.3-0.4% is covered on nodulizing agent equably, pour iron liquid, carry out spheroidizing and first time inoculation, pour residue iron liquid again, the second nucleating agent being equivalent to iron liquid weight 0.25-0.35% pours with stream, completes second time inoculation, cast, obtains ingot casting;

(3) ingot casting is heated to 950-1050 DEG C, insulation 5-6 hour, hardening is cooled to less than 100 DEG C, then ingot casting is heated to 600-700 DEG C, insulation 5-6 hour, then naturally cools to room temperature, carries out machine-shaping;

(4) whole piston is carried out surfaces nitrided process, the nitriding treatment degree of depth >=0.3mm, to obtain final product;

Described nodulizing agent is made up of the raw material of following weight part: Ba1-1.6, Mg10-12, Ca 1-1.5, Si10-13, rare earth 2-3, Fe82-86; Preparation method is; By Ba powder, Mg powder, Ca powder, Si powder, rare earth mixing, add the iron powder of 1/3, in argon atmosphere, be heated to iron powder fusing, stir, build, pulverize, cross 10 mesh sieves, obtain powder; Residue iron powder is added crucible, described powder injection is sent into the central authorities of iron powder, in argon atmosphere, be heated to 1510-1520 DEG C, roll is rolled into the thin slice that thickness is 4-5mm, then be ground into the particle that particle diameter is less than 4mm, to obtain final product;

Described first nucleating agent is made up of the raw material of following weight part: La0.1-0.3, Mg3-4, Ca2-4, Mn1-2, Nb0.4-0.7, Si25-30, Fe71-75; Preparation method is, is mixed by metal-powder, grinds 10-20 minute, to obtain final product in argon atmosphere;

Described first nucleating agent is made up of the raw material of following weight part: Y0.1-0.3, Mg2-3, Ca3-5, Mn2-4, Sr0.5-0.7, Si29-35, Fe71-75; Preparation method is, is mixed by metal-powder, grinds 10-20 minute, to obtain final product in argon atmosphere.