CN115896683A - QPQ production process based on repair and reinforcement treatment technology - Google Patents
QPQ production process based on repair and reinforcement treatment technology Download PDFInfo
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- CN115896683A CN115896683A CN202110918187.3A CN202110918187A CN115896683A CN 115896683 A CN115896683 A CN 115896683A CN 202110918187 A CN202110918187 A CN 202110918187A CN 115896683 A CN115896683 A CN 115896683A
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Abstract
The invention discloses a QPQ production process based on a repair and reinforcement treatment technology, which comprises the following steps of: the method comprises the following steps of firstly, preprocessing the surface of a test piece to obtain a surface to be processed; secondly, placing the surface to be treated in the first step into a nitriding furnace for nitriding treatment to obtain a reinforced surface; the bath salt for nitriding treatment consists of a nitriding salt, a regulating salt and a permeation assistant agent, wherein the mass ratio of the nitriding salt to the regulating salt to the permeation assistant agent is (3 to 5): (4 to 6.5): 1, the content of cyanate in bath salt is 22 to 32 percent; and step three, placing the enhanced surface in the step two in an oxidation furnace for oxidation treatment, and cooling to room temperature to obtain a QPQ heat treatment surface. Before QPQ treatment, the surface of the metal matrix is pretreated by ultrasonic shot blasting, so that the speed of the reinforcing element permeating into the surface of the matrix in the nitriding process is increased, the binding force between the composite permeating layer and the surface of the metal matrix is increased, and the wear resistance and the physical and chemical properties of the AISI440C stainless steel are improved.
Description
Technical Field
The invention relates to the technical research field of QPQ heat treatment technology, in particular to a QPQ production technology based on repair and strengthening treatment technology.
Background
QPQ treatment, which is an abbreviated form of Quench-Polish-Quench. The method is characterized in that a ferrous metal part is put into two salt baths with different properties, and a plurality of elements are infiltrated into the surface of the metal to form a composite infiltrated layer, so that the purpose of modifying the surface of the part is achieved. It is not quenched, but achieves the effect of surface quenching, so it is called QPQ abroad. The method is called as a nitrogen-carbon-oxygen composite treatment technology in China.
In the prior art, the hardness and the wear resistance of a metal surface can be improved by QPQ heat treatment, wherein the QPQ heat treatment process mainly comprises three steps of ultrasonic cleaning, nitriding and oxidizing, the ultrasonic cleaning can remove dirt on the surface to be enhanced so as to ensure that enhancing elements such as nitrogen, carbon and the like permeate into the surface of a base body in the nitriding process, the pretreatment process ensures the combination of the enhancing elements and the surface of the base body, but the formed composite infiltrated layer is thin, and the combination force between the composite infiltrated layer and the base body is poor, so that the physical and chemical properties and the mechanical properties of the metal surface can not meet the use requirements.
Disclosure of Invention
The invention aims to solve the problems that the physical and chemical properties and the mechanical properties of a metal surface cannot meet the use requirements due to the fact that a composite infiltrated layer formed by the existing QPQ heat treatment process is thin and the bonding force between the composite infiltrated layer and a substrate is poor, and provides a QPQ production process based on a repair and strengthening treatment technology.
To achieve these objects and other advantages in accordance with the purpose of the present invention, there is provided a QPQ production process based on repair and reinforcement treatment technology, the production process comprising the steps of:
the method comprises the following steps of firstly, pretreating the surface of a test piece to obtain a surface to be treated;
secondly, placing the surface to be treated in the first step into a nitriding furnace for nitriding treatment to obtain a reinforced surface;
the bath salt for nitriding treatment consists of a nitriding salt, a regulating salt and a permeation aid, wherein the mass ratio of the nitriding salt to the regulating salt to the permeation aid is (3 to 5): (4 to 6.5): 1, the content of cyanate in bath salt is 22 to 32 percent;
and step three, placing the enhanced surface in the step two in an oxidation furnace for oxidation treatment, and cooling to room temperature to obtain the QPQ heat treatment surface.
Preferably, the pretreatment in the first step includes a cleaning treatment, an ultrasonic shot blasting pretreatment, and a microetching treatment.
Preferably, the cleaning treatment method in the first step is: putting the surface of the test piece into a cleaning solution, and ultrasonically washing for 20-30min to obtain a clean test piece surface;
the cleaning solution comprises absolute ethyl alcohol, sodium dodecyl benzene sulfonate, span 80 and water, wherein the mass ratio of the absolute ethyl alcohol to the sodium dodecyl benzene sulfonate to the span 80 to the water is (2 to 2.5): (1 to 1.2): (1 to 1.2): (8 to 12).
Preferably, when the ultrasonic shot blasting pretreatment is carried out in the step one, the diameter of the impact head is 2 to 3mm, the treatment time is 20 to 30min, the frequency is 20kHz, and the coverage rate is 65%.
Preferably, the microetching treatment method in the first step is as follows: and (3) placing the surface of the test piece in a microetching solution for treatment for 3 to 7s, wherein the microetching solution is a mixture of hydrogen peroxide, benzoic acid, ethanol and fatty alcohol-polyoxyethylene ether, and the mass ratio of the hydrogen peroxide, the benzoic acid, the ethanol and the fatty alcohol-polyoxyethylene ether is (0.1 to 0.3): (0.1 to 0.3): (8 to 10): (0.1 to 0.3).
Preferably, the nitriding temperature in the nitriding treatment in the second step is 500 to 600 ℃, and the nitriding time is 60 to 180min.
Preferably, in the second step, the nitronium salt is sodium cyanate;
the adjusting salt is a mixture of potassium carbonate and potassium carbonate, and the mass ratio of the sodium carbonate to the potassium carbonate is 2:1;
the penetration aid consists of activated carbon, nickel powder and polyisobutylene succinimide, wherein the mass ratio of the activated carbon to the nickel powder to the polyisobutylene succinimide is (5 to 8): 1:1.
preferably, the bath salt in the oxidation treatment in the third step is a mixture of sodium nitrate, sodium carbonate, sodium hydroxide and potassium nitrate, wherein the mass ratio of the sodium nitrate to the sodium carbonate to the sodium hydroxide to the potassium nitrate is (10 to 15): (10 to 20): (1 to 4): (10 to 20).
Preferably, the oxidation temperature in the oxidation treatment in the third step is 300 to 380 ℃, and the salt bath oxidation time is 30 to 50min.
The invention at least comprises the following beneficial effects: before QPQ treatment, the method of ultrasonic shot blasting pretreatment is adopted to remove the original oxide layer on the surface of the test piece, so that the reinforcing elements in the nitriding bath salt directly permeate into the surface of the metal matrix, the speed of permeating the reinforcing elements into the surface of the matrix in the nitriding process is increased, the nitriding time is shortened, the surface of the test piece is subjected to ultrasonic shot blasting pretreatment and then subjected to microetching treatment, rugged microparticles can be formed on the surface of the metal matrix through the microetching treatment, so that microchannels are formed on the surface of the matrix, on one hand, the reinforcing elements can rapidly permeate into the metal matrix through the microchannels, on the other hand, the reinforcing elements are combined with the metal matrix on the walls of the microchannels, the bonding force between the composite permeated layer and the surface of the metal matrix is increased, and finally, the wear resistance and the physical and chemical and physical and chemical properties of the AISI440C stainless steel are improved.
Additional advantages, objects, and features of the invention will be set forth in part in the description which follows and in part will become apparent to those having ordinary skill in the art upon examination of the following or may be learned from practice of the invention.
Detailed Description
The present invention is described in further detail below to enable those skilled in the art to practice the invention with reference to the description.
The invention provides a QPQ production process based on a repair and strengthening treatment technology, and the production process is further explained by taking a QPQ heat treatment production process of AISI440C stainless steel as a research object.
Example 1
The production process comprises the following steps:
the method comprises the following steps of firstly, preprocessing the surface of AISI440C stainless steel to obtain a surface to be processed, wherein the preprocessing comprises cleaning processing, ultrasonic shot blasting preprocessing and micro-etching processing;
the cleaning treatment method comprises the following steps: putting the AISI440C stainless steel surface into a cleaning solution, and ultrasonically washing for 30min to obtain a clean test piece surface, wherein the cleaning solution comprises absolute ethyl alcohol, sodium dodecyl benzene sulfonate, span 80 and water, and the mass ratio of the absolute ethyl alcohol to the sodium dodecyl benzene sulfonate to the span 80 to the water is 2:1:1:8;
when ultrasonic shot blasting pretreatment is carried out, the diameter of an impact head is 2mm, the treatment time is 30min, the frequency is 20kHz, and the coverage rate is 65%;
the microetching treatment method comprises the following steps: placing the surface of a test piece in a microetching solution for treatment for 5s, wherein the microetching solution is a mixture of hydrogen peroxide, benzoic acid, ethanol and fatty alcohol-polyoxyethylene ether, and the mass ratio of the hydrogen peroxide to the benzoic acid to the ethanol to the fatty alcohol-polyoxyethylene ether is 0.2:0.1:10:0.1.
secondly, placing the surface to be treated in the first step into a nitriding furnace for nitriding treatment to obtain a reinforced surface;
the nitriding temperature in the nitriding treatment is 500 ℃, and the nitriding time is 60min;
the bath salt during nitriding treatment consists of nitridized salt, adjusting salt and a permeation aid, wherein the mass ratio of the nitridized salt to the adjusting salt to the permeation aid is 3.4:5.6:1, the content of cyanate in bath salt is 22%, the nitrosalt is sodium cyanate, the adjusting salt is a mixture of potassium carbonate and potassium carbonate, and the mass ratio of the sodium carbonate to the potassium carbonate is 2:1, the penetration enhancer consists of active carbon, nickel powder and polyisobutylene succinimide, wherein the mass ratio of the active carbon to the nickel powder to the polyisobutylene succinimide is 8:1:1.
thirdly, placing the enhanced surface in the second step in an oxidation furnace for oxidation treatment, and cooling to room temperature to obtain a QPQ heat treatment surface;
the oxidation temperature during oxidation treatment is 300 ℃, the salt bath oxidation time is 50min, the bath salt during oxidation treatment is a mixture of sodium nitrate, sodium carbonate, sodium hydroxide and potassium nitrate, and the mass ratio of the sodium nitrate to the sodium carbonate to the sodium hydroxide to the potassium nitrate is 10:10:1:10.
example 2
The present embodiment is different from embodiment 1 in that: in the first step, the surface of the test piece is placed in a microetching solution for treatment for 7s.
Example 3
The present embodiment is different from embodiment 1 in that: in the first step, the surface of the test piece is placed in a micro-etching solution for treatment for 3s.
Example 4
The present embodiment is different from embodiment 1 in that: in the second step, the mass ratio of the nitrocarburizing salt, the adjusting salt and the permeation-assisting agent is 5:4:1, the content of cyanate in the bath salt is 32 percent.
Example 5
The present embodiment is different from embodiment 1 in that: in the second step, the mass ratio of nitrifying salt, adjusting salt and the permeation aid is 4.3:4.7:1, the content of cyanate in the bath salt is 28%.
Example 6
The present embodiment is different from embodiment 1 in that: in the second step, the mass ratio of nitrifying salt, adjusting salt and the permeation aid is 4.6:4.4:1, the content of cyanate in bath salt is 30 percent;
the nitriding temperature in the nitriding treatment is 600 ℃, and the nitriding time is 180min.
Example 7
The present embodiment is different from embodiment 1 in that: in the second step, the mass ratio of nitrifying salt, adjusting salt and the permeation aid is 4.6:4.4:1, the content of cyanate in bath salt is 30 percent;
the oxidation temperature during the oxidation treatment is 380 ℃, and the salt bath oxidation time is 30min.
Comparative example 1
The production process comprises the following steps:
step one, the surface of the stainless steel AISI440C produced in the same batch as the embodiment is pretreated to obtain a surface to be treated, and the pretreatment is cleaning treatment;
the cleaning treatment method comprises the following steps: putting the surface of the AISI440C stainless steel into a cleaning solution, and ultrasonically cleaning for 30min to obtain a clean test piece surface, wherein the cleaning solution comprises absolute ethyl alcohol, sodium dodecyl benzene sulfonate, span 80 and water, and the mass ratio of the absolute ethyl alcohol to the sodium dodecyl benzene sulfonate to the span 80 to the water is 2:1:1:8;
secondly, placing the surface to be treated in the first step into a nitriding furnace for nitriding treatment to obtain a reinforced surface;
the nitriding temperature in the nitriding treatment is 600 ℃, and the nitriding time is 180min;
the bath salt during nitriding treatment consists of nitriding salt, adjusting salt and a permeation aid, wherein the mass ratio of the nitriding salt to the adjusting salt to the permeation aid is 4.6:4.4:1, the content of cyanate in bath salt is 30%, the nitrifying salt is sodium cyanate, the adjusting salt is a mixture of potassium carbonate and potassium carbonate, and the mass ratio of the sodium carbonate to the potassium carbonate is 2:1, the penetration enhancer consists of active carbon, nickel powder and polyisobutylene succinimide, wherein the mass ratio of the active carbon to the nickel powder to the polyisobutylene succinimide is 8:1:1.
thirdly, placing the enhanced surface in the second step in an oxidation furnace for oxidation treatment, and cooling to room temperature to obtain a QPQ heat treatment surface;
the oxidation temperature during oxidation treatment is 300 ℃, the salt bath oxidation time is 50min, the bath salt during oxidation treatment is a mixture of sodium nitrate, sodium carbonate, sodium hydroxide and potassium nitrate, and the mass ratio of the sodium nitrate to the sodium carbonate to the sodium hydroxide to the potassium nitrate is 10:10:1:10.
comparative example 2
Step one, performing pretreatment on the surface of the AISI440C stainless steel produced in the same batch as the embodiment to obtain a surface to be treated, wherein the pretreatment comprises cleaning treatment and ultrasonic shot blasting pretreatment;
the cleaning treatment method comprises the following steps: putting the surface of the AISI440C stainless steel into a cleaning solution, and ultrasonically cleaning for 30min to obtain a clean test piece surface, wherein the cleaning solution comprises absolute ethyl alcohol, sodium dodecyl benzene sulfonate, span 80 and water, and the mass ratio of the absolute ethyl alcohol to the sodium dodecyl benzene sulfonate to the span 80 to the water is 2:1:1:8;
when the ultrasonic shot blasting is used for pretreatment, the diameter of an impact head is 2mm, the treatment time is 30min, the frequency is 20kHz, and the coverage rate is 65%.
Secondly, placing the surface to be treated in the first step into a nitriding furnace for nitriding treatment to obtain a reinforced surface;
the nitriding temperature in the nitriding treatment is 500 ℃, and the nitriding time is 60min;
the bath salt during nitriding treatment consists of nitriding salt, adjusting salt and a permeation aid, wherein the mass ratio of the nitriding salt to the adjusting salt to the permeation aid is 4.6:4.4:1, the content of cyanate in bath salt is 30%, the nitrifying salt is sodium cyanate, the adjusting salt is a mixture of potassium carbonate and potassium carbonate, and the mass ratio of the sodium carbonate to the potassium carbonate is 2:1, the penetration enhancer consists of active carbon, nickel powder and polyisobutylene succinimide, wherein the mass ratio of the active carbon to the nickel powder to the polyisobutylene succinimide is 8:1:1.
thirdly, placing the enhanced surface in the second step in an oxidation furnace for oxidation treatment, and cooling to room temperature to obtain a QPQ heat treatment surface;
the oxidation temperature during oxidation treatment is 300 ℃, the salt bath oxidation time is 50min, the bath salt during oxidation treatment is a mixture of sodium nitrate, sodium carbonate, sodium hydroxide and potassium nitrate, and the mass ratio of the sodium nitrate to the sodium carbonate to the sodium hydroxide to the potassium nitrate is 10:10:1:10.
before QPQ treatment is carried out in the production process, an ultrasonic shot blasting pretreatment method is adopted to remove an original oxide layer on the surface of AISI440C stainless steel, so that a reinforcing element in nitriding bath salt directly permeates into the surface of a metal matrix, the speed of permeating the reinforcing element into the surface of the matrix in the nitriding process is increased, the nitriding time is shortened, the surface of a test piece is subjected to ultrasonic shot blasting pretreatment and then subjected to microetching treatment, rugged microparticles can be formed on the surface of the metal matrix through the microetching treatment, microchannels can be formed on the surface of the matrix, on one hand, the reinforcing element can rapidly permeate into the metal matrix through the microchannels, on the other hand, the reinforcing element is combined with the metal matrix on the walls of the microchannels, the bonding force of a composite permeation layer and the surface of the metal matrix is increased, and finally, the wear resistance and the physical and chemical and physical and chemical properties of AISI440C stainless steel are improved. The beneficial effects of the scheme of the invention are verified by hardness tests and wear resistance tests.
The method comprises the following steps of measuring the surface hardness of an AISI440C stainless steel sample by adopting an HVS-1000A digital display microhardness tester, measuring the abrasion loss of the AISI440C stainless steel by adopting an MFT-5000 type multifunctional friction abrasion tester, and testing the abrasion loss of the AISI440C stainless steel by adopting the following steps: setting equipment parameters: the abrasion loss of the sample was calculated by using a silicon nitride friction ball having a diameter of 10mm as a friction medium under a load of 50N, a frequency of 1Hz, a friction time of 30min, and a reciprocating stroke of 10mm, and the test results are shown in the following table:
| test specimen | Surface hardness/HV | Abrasion loss/mg |
| Example 1 | 1277 | 2.04 |
| Example 2 | 1459 | 2.37 |
| Example 3 | 1481 | 2.91 |
| Example 4 | 1498 | 3.01 |
| Example 5 | 1174 | 3.25 |
| Example 6 | 1353 | 1.96 |
| Example 7 | 1238 | 1.88 |
| Comparative example 1 | 928 | 3.47 |
| Comparative example 2 | 1034 | 3.15 |
As can be seen from the table, the prior oxide layer on the surface of the AISI440C stainless steel can be removed by adopting the pretreatment methods of ultrasonic shot blasting pretreatment and microetching treatment before QPQ treatment is carried out, so that the strengthening elements in the nitriding bath salt can directly permeate into the surface of the metal matrix, the speed of the strengthening elements permeating into the surface of the matrix in the nitriding process is accelerated, and the nitriding time is shortened; the micro-etching treatment can form rugged microparticles on the surface of the AISI440C stainless steel substrate, so that a micro-channel is formed on the surface of the substrate, on one hand, the reinforcing element can rapidly permeate into the metal substrate through the micro-channel, on the other hand, the reinforcing element is combined with the metal substrate on the wall of the micro-channel, the binding force of the composite permeation layer and the surface of the metal substrate is increased, and finally, the wear resistance and the physical and chemical properties of the AISI440C stainless steel are improved.
While embodiments of the invention have been disclosed above, it is not limited to the applications listed in the description and the embodiments. It can be applied to all kinds of fields suitable for the present invention. Additional modifications will readily occur to those skilled in the art. The invention is therefore not to be limited to the specific details described above without departing from the general concept defined by the appended claims and their equivalents.
Claims (9)
1. A QPQ production process based on a repair and reinforcement treatment technology is characterized by comprising the following steps:
the method comprises the following steps of firstly, preprocessing the surface of a test piece to obtain a surface to be processed;
step two, placing the surface to be processed in the step one in a nitriding furnace for nitriding treatment to obtain an enhanced surface;
the bath salt for nitriding treatment consists of a nitriding salt, a regulating salt and a permeation aid, wherein the mass ratio of the nitriding salt to the regulating salt to the permeation aid is (3 to 5): (4 to 6.5): 1, the content of cyanate in bath salt is 22 to 32 percent;
and step three, placing the enhanced surface in the step two in an oxidation furnace for oxidation treatment, and cooling to room temperature to obtain a QPQ heat treatment surface.
2. The QPQ production process based on repair and strengthening treatment technique according to claim 1, wherein the pretreatment in the first step comprises a cleaning treatment, an ultrasonic shot peening pretreatment and a microetching treatment.
3. The QPQ production process based on repair and enhancement treatment technique according to claim 2, wherein the cleaning treatment in step one is: putting the surface of the test piece into a cleaning solution, and ultrasonically washing for 20-30min to obtain a clean test piece surface;
the cleaning solution comprises absolute ethyl alcohol, sodium dodecyl benzene sulfonate, span 80 and water, wherein the mass ratio of the absolute ethyl alcohol to the sodium dodecyl benzene sulfonate to the span 80 to the water is (2 to 2.5): (1 to 1.2): (1 to 1.2): (8 to 12).
4. The QPQ production process based on the repair and reinforcement treatment technology as claimed in claim 2, wherein when the ultrasonic shot blasting pretreatment is carried out in the step one, the diameter of the impact head is 2-3 mm, the treatment time is 20-30min, the frequency is 20kHz, and the coverage rate is 65%.
5. The QPQ production process based on repair and enhancement treatment technique according to claim 2, wherein the microetching treatment in the first step is: and (3) placing the surface of the test piece in a microetching solution for treatment for 3 to 7s, wherein the microetching solution is a mixture of hydrogen peroxide, benzoic acid, ethanol and fatty alcohol-polyoxyethylene ether, and the mass ratio of the hydrogen peroxide, the benzoic acid, the ethanol and the fatty alcohol-polyoxyethylene ether is (0.1 to 0.3): (0.1 to 0.3): (8 to 10): (0.1 to 0.3).
6. The QPQ production process based on the repair and reinforcement treatment technology as claimed in claim 1, wherein the nitriding temperature in the nitriding treatment in the second step is 500-600 ℃, and the nitriding time is 60-180min.
7. The QPQ production process based on repair and strengthening treatment technique according to claim 1, wherein in step two the nitronium salt is sodium cyanate;
the adjusting salt is a mixture of potassium carbonate and potassium carbonate, and the mass ratio of the sodium carbonate to the potassium carbonate is 2:1;
the penetration enhancer consists of active carbon, nickel powder and polyisobutylene succinimide, wherein the mass ratio of the active carbon to the nickel powder to the polyisobutylene succinimide is (5 to 8): 1:1.
8. the QPQ production process based on the repair and reinforcement treatment technology according to claim 1, wherein the bath salt in the oxidation treatment in the third step is a mixture of sodium nitrate, sodium carbonate, sodium hydroxide and potassium nitrate, and the mass ratio of the sodium nitrate to the sodium carbonate to the sodium hydroxide to the potassium nitrate is (10-15): (10 to 20): (1 to 4): (10 to 20).
9. The QPQ production process based on the repair and reinforcement treatment technology according to claim 1, wherein the oxidation temperature in the oxidation treatment in the third step is 300-380 ℃, and the salt bath oxidation time is 30-50min.
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