CN104878278A - Lasting high-strength casting material for hydraulic wrench piston and preparation method of lasting high-strength casting material - Google Patents

Abstract

The invention provides a lasting high-strength casting material for a hydraulic wrench piston. The lasting high-strength casting material contains the following chemical element components in percentage by mass: 1.3-1.8% of Cr, 2.1-2.5% of C, 1.2-1.5% of Mn, 0.08-0.13% of Mg, 0.3-0.6% of Mo, 4.2-4.6% of Si, 0.03-0.05% of Sr, less than or equal to 0.03% of S, 0.02-0.04% of P and the balance of Fe. The piston material has high hardness and extremely high wear resistance; due to the addition of Mo and Cr, the graphitization of the piston material is promoted, the high temperature oxidation resistance of the piston material is improved, and the piston is enabled to have lasting high strength; the production method is capable of enhancing the crack resistance of the casting, improving the hardness and the abrasion resistance of the surface of the piston and prolonging the service life of the piston; and a nodulizing agent and a nucleating agent are adopted to make the roundness of the graphite better, and therefore, the mechanical properties of the ductile cast iron casting can be effectively improved, and the tensile strength of the casting is high.

Description

A kind of hydraulic spanner piston lasting high strength casting material and preparation method thereof

Technical field

The present invention relates to casting technology field, particularly relate to a kind of hydraulic spanner piston lasting high strength casting 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 hydraulic spanner piston lasting high strength casting material and preparation method thereof, this piston material has high hardness and high wear resisting property, and high temperature oxidation resistance is good, makes piston have lasting high strength.

Technical scheme of the present invention is as follows:

The lasting high strength casting material of a kind of hydraulic spanner piston, is characterized in that: the chemical element composition that it contains and mass percent thereof are: Cr1.3-1.8, C2.1-2.5, Mn1.2-1.5, Mg0.08-0.13, Mo0.3-0.6, Si4.2-4.6, Sr0.03-0.05, S≤0.03, P0.02-0.04, all the other are Fe.

The described hydraulic spanner piston production method of lasting high strength casting 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, again ingot casting is heated to 600-700 DEG C, insulation 3-4 hour, then be cooled to 300-350 DEG C with the speed of 1-1.5 DEG C/minute, insulation 2-3 hour, naturally cool to room temperature again, carry 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 has high hardness and high wear resisting property, by adding Mo and Cr, facilitating greying, improve high temperature oxidation resistance, making piston have lasting high strength; 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

The lasting high strength casting material of a kind of hydraulic spanner piston, the chemical element composition that it contains and mass percent thereof are: Cr1.3-1.8, C2.1-2.5, Mn1.2-1.5, Mg0.08-0.13, Mo0.3-0.6, Si4.2-4.6, Sr0.03-0.05, S≤0.03, P0.02-0.04, all the other are Fe.

The described hydraulic spanner piston production method of lasting high strength casting 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, again ingot casting is heated to 650 DEG C, is incubated 3.5 hours, then is cooled to 330 DEG C with the speed of 1.3 DEG C/minute, be incubated 2.5 hours, then naturally cool 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 611MPa to the material of this embodiment, and unit elongation is 11.1%, and yield strength is 395MPa, and surface hardness is 189HBW, and toughness is 8.9J/ ㎡.

Claims (2)

1. the lasting high strength casting material of hydraulic spanner piston, is characterized in that: the chemical element composition that it contains and mass percent thereof are: Cr1.3-1.8, C2.1-2.5, Mn1.2-1.5, Mg0.08-0.13, Mo0.3-0.6, Si4.2-4.6, Sr0.03-0.05, S≤0.03, P0.02-0.04, all the other are Fe.

2. the hydraulic spanner piston according to claim 1 production method of lasting high strength casting 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, again ingot casting is heated to 600-700 DEG C, insulation 3-4 hour, then be cooled to 300-350 DEG C with the speed of 1-1.5 DEG C/minute, insulation 2-3 hour, naturally cool to room temperature again, carry 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.