Disclosure of Invention
The invention aims to provide a corrosion-resistant metal coating of a 20CrMnTi steel passive helical gear of a differential mechanism, aiming at improving the corrosion resistance and the wear resistance of the passive helical gear and further prolonging the service life of the passive helical gear.
The invention provides a corrosion-resistant metal coating of a 20CrMnTi steel passive helical gear of a differential mechanism, wherein the 20CrMnTi steel passive helical gear comprises the following chemical element components in percentage by mass: c: 0.18% -0.22%, Si: 0.25% -0.3%, Mn: 0.5% -0.9%, Cr: 1.2% -2.0%, Ti: 0.02% -0.08%, P <0.04%, S <0.04%, the balance being iron; the corrosion-resistant metal coating comprises the following chemical element components in percentage by mass: c: 0.06-0.08%, Cr: 20-30%, Ni: 12.25-15.43%, Al 1.5-3%, Ti 0.1-0.2%, Cu: 0.3-0.5%, Mg: 0.13-0.15%, Re 0.3-0.5%, La: 0.32-0.38%, Ce: 0.2-0.52%, the balance being iron; the treatment process of the corrosion-resistant metal coating is carried out according to the following steps:
step S1: preparing a powder core wire material: mixing, molding and drawing C, Cr, Ni, Al, Ti, Cu, Mg, Re, La and Ce to obtain powder core wires;
step S2: surface treatment: after two-stage quenching, the differential 20CrMnTi steel driven bevel gear is put into an RX3 box-type electric furnace for first tempering treatment;
step S3: the spraying process comprises the following steps: immediately spraying a powder core wire material on the surface of the gear to form a corrosion-resistant metal coating after the differential 20CrMnTi steel passive helical gear is tempered for the first time;
step S4: and (3) tempering for the second time: and then carrying out secondary tempering treatment on the sprayed 20CrMnTi steel passive helical gear of the differential.
As a further improvement of the present invention, the process of the first tempering treatment in step S2 is: the tempering temperature is 500-650 ℃, the temperature is kept for 2h, and the oil is cooled to the room temperature.
As a further improvement of the present invention, the process of the second tempering treatment in step S4 is: the tempering temperature is 650 plus 700 ℃, the temperature is kept for 1.5h, and the air is blown and cooled to the room temperature.
As a further improvement of the present invention, the spraying process parameters in step S3 are: the voltage is 28-30V, the current is 160-240A, the spraying distance is 80-100mm, and the pressure of compressed air is 0.4-0.6 MPa.
As a further improvement of the present invention, the spraying process parameters in step S3 are: the voltage is 30V, the current is 220A, the spraying distance is 80mm, and the pressure of compressed air is 0.4 MPa.
As a further improvement of the invention, the corrosion-resistant metal coating comprises the following components in percentage by mass: c: 0.07-0.08%, Cr: 25-30%, Ni: 14.25-15.43%, Al 2.0-3%, Ti 0.15-0.2%, Cu: 0.4-0.5%, Mg: 0.14-0.15%, Re 0.4-0.5%, La: 0.35-0.38%, Ce: 0.35-0.52%, the balance being iron.
As a further improvement of the invention, the thickness of the corrosion-resistant metal coating is: 0.3-0.5 mm.
Compared with the prior art, the invention has the following beneficial effects:
1. the method is different from the common spraying process of spraying the anti-corrosion metal coating on the surface of the finished transmission part, is improved by combining the production heat treatment process when the passive helical gear is not formed into a finished product, and has the advantages of small porosity of the sprayed anti-corrosion coating, high compactness of the metal coating and high anti-stripping strength of the metal coating, so that the obtained anti-corrosion metal coating has high anti-corrosion performance.
2. According to the invention, the passive helical gear is sprayed after the first tempering, the stay time of the passive helical gear and the elements such as Cr, C, Ni and Ce in the anti-corrosion metal coating is long at high temperature, the elements such as Cr, C, Ni and Ce in the anti-corrosion metal coating are transferred into the passive helical gear, and then the elements transferred into the passive helical gear are tempered for the second time, so that the elements such as Ce play a role, the internal structure of the passive helical gear is refined, the internal stress is eliminated and the cracks after quenching are repaired, the content limit of the elements such as Cr, C and Ce in the forging process of the passive helical gear is also expanded, the content of the elements such as Cr, C and Ni in the passive helical gear is improved in a coating mode.
3. The rare earth element Ce is adopted, the structure performance of the material can be obviously improved, the grain refinement degree is improved, the compactness of the powder core wire is increased, the pores on the surface of the coating are further reduced, the coating is sprayed on the high-temperature surface after the first tempering to form the coating, the time for the coating to contact with a high-temperature matrix is long, and the element Ce permeates into the passive helical gear, so that the grains of the passive helical gear are finer and more disordered, the original austenite grains are effectively segmented, the growth space of a second tempering phase change structure is limited, the refined structure is achieved, the substructure in the original austenite grains is diversified, and the impact toughness of the passive helical gear is increased.
Detailed Description
The technical solution of the present invention will be clearly and completely described below with reference to specific embodiments. It is to be understood that the described embodiments are merely a few embodiments of the invention, and not all embodiments. All other embodiments, which can be derived by a person skilled in the art from the embodiments of the present invention without any inventive step, are within the scope of the present invention.
The invention discloses a corrosion-resistant metal coating of a 20CrMnTi steel passive helical gear of a differential mechanism, and the specific implementation mode is as follows.
Example 1
The invention provides a corrosion-resistant metal coating of a 20CrMnTi steel passive helical gear of a differential mechanism, wherein the 20CrMnTi steel passive helical gear comprises the following chemical element components in percentage by mass: c: 0.18% -0.22%, Si: 0.25% -0.3%, Mn: 0.5% -0.9%, Cr: 1.2% -2.0%, Ti: 0.02% -0.08%, P <0.04%, S <0.04%, the balance being iron; the corrosion-resistant metal coating comprises the following chemical element components in percentage by mass: c: 0.0%, Cr: 20%, Ni: 12.25%, Al 1.5%, Ti 0.1%, Cu: 0.3%, Mg: 0.13%, Re:0.3%, La: 0.32%, Ce: 0.2%, the balance being iron; the treatment process of the corrosion-resistant metal coating is carried out according to the following steps:
step S1: preparing a powder core wire material: mixing, molding and drawing C, Cr, Ni, Al, Ti, Cu, Mg, Re, La and Ce to obtain powder core wires;
step S2: surface treatment: after two-stage quenching, the differential 20CrMnTi steel driven helical gear is put into an RX3 box type electric furnace for the first tempering treatment of tempering temperature of 500 ℃, heat preservation for 2 hours and oil cooling to room temperature;
step S3: the spraying process comprises the following steps: immediately spraying a powder core wire material on the surface of the gear to form a corrosion-resistant metal coating under the conditions that the parameters of the powder core wire material are 28-30V of voltage, 160-240A of current, 80-100mm of spraying distance and 0.4-0.6MPa of compressed air after the first tempering of the differential 20CrMnTi steel passive helical gear, wherein the thickness of the corrosion-resistant coating is 0.3 mm;
step S4: and (3) tempering for the second time: and then carrying out secondary tempering treatment on the sprayed 20CrMnTi steel driven helical gear of the differential mechanism at the tempering temperature of 650 ℃, preserving heat for 1.5h, and carrying out air blast cooling to room temperature.
Example 2
The invention provides a corrosion-resistant metal coating of a 20CrMnTi steel passive helical gear of a differential mechanism, wherein the 20CrMnTi steel passive helical gear comprises the following chemical element components in percentage by mass: c: 0.18% -0.22%, Si: 0.25% -0.3%, Mn: 0.5% -0.9%, Cr: 1.2% -2.0%, Ti: 0.02% -0.08%, P <0.04%, S <0.04%, the balance being iron; the corrosion-resistant metal coating comprises the following chemical element components in percentage by mass: c: 0.08%, Cr: 30%, Ni: 15.43%, Al 3%, Ti 0.2%, Cu: 0.5%, Mg: 0.15%, Re 0.5%, La: 0.38%, Ce: 0.52%, the balance being iron; the treatment process of the corrosion-resistant metal coating is carried out according to the following steps:
step S1: preparing a powder core wire material: mixing, molding and drawing C, Cr, Ni, Al, Ti, Cu, Mg, Re, La and Ce to obtain powder core wires;
step S2: surface treatment: after two-stage quenching, the differential 20CrMnTi steel driven helical gear is put into an RX3 box type electric furnace for the first tempering treatment of tempering temperature of 650 ℃, heat preservation for 2 hours and oil cooling to room temperature;
step S3: the spraying process comprises the following steps: immediately spraying a powder core wire material on the surface of the gear to form a corrosion-resistant metal coating under the conditions that the parameters of the powder core wire material are 28-30V of voltage, 160-240A of current, 80-100mm of spraying distance and 0.4-0.6MPa of compressed air after the first tempering of the differential 20CrMnTi steel passive helical gear, wherein the thickness of the corrosion-resistant coating is 0.5 mm;
step S4: and (3) tempering for the second time: and then carrying out secondary tempering treatment on the sprayed 20CrMnTi steel driven helical gear of the differential mechanism at the tempering temperature of 700 ℃, preserving the heat for 1.5h, and carrying out air blast cooling to the room temperature.
Example 3
The invention provides a corrosion-resistant metal coating of a 20CrMnTi steel passive helical gear of a differential mechanism, wherein the 20CrMnTi steel passive helical gear comprises the following chemical element components in percentage by mass: c: 0.18% -0.22%, Si: 0.25% -0.3%, Mn: 0.5% -0.9%, Cr: 1.2% -2.0%, Ti: 0.02% -0.08%, P <0.04%, S <0.04%, the balance being iron; the corrosion-resistant metal coating comprises the following chemical element components in percentage by mass: c: 0.07%, Cr: 25%, Ni: 14.25%, Al 2%, Ti 0.15%, Cu: 0.4%, Mg: 0.14%, Re:0.4%, La: 0.35%, Ce: 0.35%, the balance being iron; the treatment process of the corrosion-resistant metal coating is carried out according to the following steps:
step S1: preparing a powder core wire material: mixing, molding and drawing C, Cr, Ni, Al, Ti, Cu, Mg, Re, La and Ce to obtain powder core wires;
step S2: surface treatment: after two-stage quenching, the differential 20CrMnTi steel driven helical gear is put into an RX3 box-type electric furnace to be subjected to first tempering treatment at the tempering temperature of 600 ℃, heat preservation for 2 hours and oil cooling to room temperature;
step S3: the spraying process comprises the following steps: immediately spraying a powder core wire material on the surface of the gear to form a corrosion-resistant metal coating under the conditions that the parameters of the powder core wire material are 28-30V of voltage, 160-240A of current, 80-100mm of spraying distance and 0.4-0.6MPa of compressed air after the first tempering of the differential 20CrMnTi steel passive helical gear, wherein the thickness of the corrosion-resistant coating is 0.4 mm;
step S4: and (3) tempering for the second time: and then carrying out secondary tempering treatment on the sprayed 20CrMnTi steel driven helical gear of the differential mechanism at the tempering temperature of 680 ℃, preserving the heat for 1.5h, and carrying out air blast cooling to the room temperature.
The prepared passive helical gear is selected as a sample to be tested for the adhesion performance according to GB/T9286-1998, the salt water resistance performance is tested according to the GB 1763-: table 1 shows the corrosion resistance test results of the passive helical gear.
The results of examples 1-3 show that the corrosion-resistant metal coating provided by the invention has good adhesion performance and high salt water and salt mist resistance.
The corrosion-resistant metal coating of the differential 20CrMnTi steel passive helical gear provided by the invention is provided. The principles and embodiments of the present invention are explained herein using specific examples, which are set forth only to help understand the method and its core ideas of the present invention. It should be noted that, for those skilled in the art, it is possible to make various improvements and modifications to the present invention without departing from the principle of the present invention, and those improvements and modifications also fall within the scope of the claims of the present invention.