CN115449607A - Method for determining isothermal gas quenching process parameters for prolonging service life of cold-work die material - Google Patents
Method for determining isothermal gas quenching process parameters for prolonging service life of cold-work die material Download PDFInfo
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Abstract
The invention relates to a method for determining isothermal gas quenching process parameters for prolonging the service life of a cold-work die material. The technical scheme is as follows: selecting 5 factors of quenching temperature, heat preservation time, gas quenching pressure, isothermal temperature and isothermal time to carry out 3-level orthogonal test design, and establishing L 18 (3 5 ) An orthogonal test table; using 18 x 3 blocks of die materials as original samples, carrying out isothermal gas quenching according to the scheme in an orthogonal test table, and measuring the hardness of each group of samples subjected to isothermal gas quenching (hereinafter referred to as samples); and sequentially and respectively carrying out room temperature impact test, wear resistance test and tensile test on 3 test samples in each group. And obtaining a comprehensive performance index delta i of the sample according to the Rockwell hardness Hi, the impact toughness alpha ki, the abrasion loss Mi and the tensile strength YSi, and selecting the process parameter of isothermal gas quenching corresponding to the maximum value of the delta i as a basis for determining the parameter in the production of the cold-work die material. The invention can lead the cold-work die material to be subjected to isothermal gas quenchingAnd various performances are greatly improved, and the service life of the die is prolonged.
Description
Technical Field
The invention belongs to the technical field of vacuum isothermal quenching methods. In particular to a method for determining isothermal gas quenching process parameters for prolonging the service life of a cold-work die material.
Background
Isothermal gas quenching refers to an isothermal quenching process in which an inert gas is used in a vacuum gas quenching furnace to perform isothermal quenching on a mold in order to achieve smooth quenching of the mold material. The method is characterized by no decarburization and no oxidation after the die is quenched, small deformation, high surface smoothness and environmental protection. When the isothermal gas quenching process parameters are not matched with the corresponding die materials, the problems that the structure distribution of the die materials after quenching is uneven, the performance does not reach the standard, cracking is easy to occur in subsequent treatment and the like occur, and the service life of the die materials is seriously influenced. Therefore, each die material needs the corresponding isothermal gas quenching process parameters, so that the performance of the material is improved through the isothermal gas quenching process, and the service life of the die is prolonged.
Wanlijun et al (Wanlijun, mianxin. Cr12MoV steel, hardness and metallographic structure analysis under different heat treatment conditions [ J ] die industry, 2005 (09): 52-56.) studied hardness changes after quenching and tempering at different temperatures using Cr12MoV cold work die steel as a study object. The research shows that: the quenching temperature is 1010-1040 ℃, and the obtained die steel has good performance. However, the conventional heat treatment process adopted in the literature is easy to form irregular network carbide, cracking and peeling are easy to form at the stress part of the die, and the service life of the die is poor.
Suliwu et al (Suliwu. Vacuum heat treatment process of DIEVAR die steel [ J ] Heat treatment, 2017,32 (1): 36-39.) studied the effect of different quenching temperatures on DIEVAR die steel with DIEVAR die steel as the study object, and obtained the conclusion that: under the condition of the same quenching pressure, the higher the quenching temperature is, the higher the hardness of the steel is, the optimal process parameters of the DIEVAR die steel are the quenching temperature of 1020 ℃ and the quenching pressure of 4.5bar. However, the process parameters provided herein are not comprehensive and cannot be used for actual production, and no standard or complete method for determining optimal process parameters is given.
The patent technology of vacuum heat treatment technology of CrWMn die steel (CN 202010933061.9) discloses quenching temperature, heat preservation time and quenching pressure of cold-work dies with different sizes. However, isothermal time and isothermal temperature in the process parameters are not disclosed, and a method for determining the process parameters is not given, and the specific values of the process parameters are only suitable for CrWMn cold-work die steel.
Disclosure of Invention
The present invention is directed to overcoming the deficiencies of the prior art. Aims to provide a method for determining isothermal gas quenching process parameters for prolonging the service life of a cold-work die material; the method is suitable for determining the isothermal gas quenching process parameters of various cold-work die materials, and the determined process parameters can be used as the basis for determining the isothermal gas quenching process parameters of the cold-work die materials in industrial production, so that the performance and the service life of the cold-work die materials can be improved.
In order to achieve the purpose, the technical scheme adopted by the invention comprises the following steps:
The ranges of the 5 process parameters: the quenching temperature is 950-1050 ℃, the heat preservation time is 10-40 min, the gas quenching pressure is 3-9 bar, the isothermal temperature is 200-280 ℃, and the isothermal time is 1-3 h.
And 2, selecting 18 multiplied by 3 cold-work die materials produced in the same batch as 18 groups of original samples, wherein each group comprises 3 blocks.
And 3, selecting 3 original samples in the 1 st group, and carrying out isothermal gas quenching according to the 1 st group orthogonal test scheme in the step 1 to obtain the 3 samples in the 1 st group after isothermal gas quenching.
And (3) selecting 3 original samples in the group 2, and carrying out isothermal gas quenching according to the orthogonal test scheme in the group 2 in the step 1 to obtain 3 isothermal gas quenched samples in the group 2.
And so on;
and (3) selecting the 3 original samples in the 18 th group, and carrying out isothermal gas quenching according to the 18 th group orthogonal test scheme in the step 1 to obtain the 3 isothermal gas quenched samples in the 18 th group.
And 4, respectively measuring the hardness of the 18 groups obtained in the step 3 and 3 isothermal gas quenching samples thereof according to the requirements of GB/T230.1-2004 Rockwell hardness test method:
selecting 7 points on the upper surface of a 1 st isothermal gas quenching sample of the first group to measure the hardness, wherein the hardness value of the 1 st isothermal gas quenching sample is the average value of 5 hardness values obtained by removing the maximum value and the minimum value; measuring the hardness values of the other 2 samples in the 1 st group; further, an average value H1 of the hardness of the sample after isothermal gas quenching of group 1, 3 blocks was obtained.
And so on;
the average value Hi of the hardness of the 3 isothermal gas-quenched samples in each group is obtained.
And 5, taking one of the 1 st group of samples subjected to isothermal gas quenching obtained in the step 4, carrying out linear cutting, processing the sample into four room-temperature impact test samples with the size of 10mm multiplied by 55mm, respectively carrying out room-temperature impact tests according to GB/T229-2007 metallic material Charpy pendulum impact test method, measuring the impact toughness of the four room-temperature impact test samples in the 1 st group, and obtaining the average value alpha k1 of the impact toughness of the four room-temperature impact test samples in the 1 st group.
And so on;
and obtaining the average value alpha ki of the impact toughness of each group of samples subjected to isothermal gas quenching.
And 6, firstly, taking one sample from each group of isothermal gas-quenched samples obtained in the step 4, carrying out linear cutting, processing the samples into wear samples, respectively carrying out room-temperature wear tests on a friction wear tester according to ASTM standard D:3702-94 (1999), and then measuring by adopting a weighing method to obtain the wear loss Mi of each group of wear samples.
And 7, according to the provisions of GB 228-2002 'Metal Material Room temperature tensile test method', respectively carrying out wire cutting on the last sample in each group of isothermal gas quenched samples obtained in the step 4, processing the samples into tensile samples with specified dimensions, and then sequentially carrying out tensile test to obtain the tensile strength YSi of each group of tensile samples.
Step 8, obtaining the comprehensive performance index delta i of the sample after isothermal gas quenching according to the Rockwell hardness Hi, the impact toughness alpha ki, the abrasion Mi and the tensile strength YSi which are measured in the steps 4 to 7
In formula (1):
hi represents the average value of the hardness of any group of samples after isothermal gas quenching, and the unit is HRC;
alpha ki represents the average value of the impact toughness of any group of samples after isothermal gas quenching, and the unit is J/cm 2 ；
Mi represents the abrasion loss of any group of samples after isothermal gas quenching, and the unit is mg;
YSi represents the tensile strength of any group of samples after isothermal gas quenching, and the unit is MPa;
and delta i represents the comprehensive performance index of any group of samples after isothermal gas quenching.
In steps 4 to 8, i represents the number of sample groups corresponding to any one of 18 orthogonal test protocols, and i is a natural number of 1 to 18.
And 9, selecting isothermal gas quenching process parameters corresponding to a group of test schemes with the largest delta i value from the comprehensive performance indexes delta i obtained in the step 8, and using the isothermal gas quenching process parameters as a basis for determining isothermal gas quenching process parameters of the cold-work die material in industrial production.
Compared with the prior art, the method has the following positive effects:
1. the invention determines the ranges of quenching temperature, heat preservation time, gas quenching pressure, isothermal temperature and isothermal time, carries out orthogonal test design according to 5-factor-3 level, and establishes L 18 (3 5 ) The method is suitable for determining the isothermal gas quenching process parameters of various cold-work die materials, and can improve the performance of the cold-work die materials and prolong the service life of the cold-work die.
2. The invention reasonably configures 5 technological parameters of the cold-work die material isothermal gas quenching, and carries out isothermal gas quenching treatment on the cold-work die material under the technological parameters, and the test results show that: hardness, impact toughness, wearability, tensile strength of mould material all promote, find the intensive degree of dimple wherein and improve after detecting the fracture of steel, observe through scanning electron microscope picture: compared with the conventional heat treatment, the strip carbide of the cold-work die material subjected to isothermal gas quenching by adopting the process parameters determined by the invention disappears, the carbide is uniformly distributed, and the metal crystal grains are smaller. Therefore, the process parameters determined by the invention can improve the performance of the quenched cold-work die material, thereby prolonging the service life of the die.
Therefore, the method is suitable for determining the isothermal gas quenching process parameters of various cold-work die materials, and the determined process parameters can be used as the basis for determining the isothermal gas quenching process parameters of the cold-work die materials in industrial production, so that the performance and the service life of the cold-work die materials can be improved.
Drawings
FIG. 1 is a scanning electron microscope image of cold-work die steel after isothermal gas quenching using the process parameters determined by the present invention;
FIG. 2 is a scanning electron micrograph of a cold work die steel after a conventional heat treatment.
Detailed description of the invention
The invention is further described with reference to the following figures and detailed description, without limiting its scope.
A method for determining isothermal gas quenching process parameters for prolonging the service life of a cold-work die material. The determination method described in this embodiment is:
The ranges of the 5 process parameters: the quenching temperature is 950-1050 ℃, the heat preservation time is 10-40 min, the gas quenching pressure is 3-9 bar, the isothermal temperature is 200-280 ℃, and the isothermal time is 1-3 h.
And 2, selecting 18 multiplied by 3 cold-work die materials produced in the same batch as 18 groups of original samples, wherein each group comprises 3 blocks.
And 3, selecting 3 original samples in the 1 st group, and carrying out isothermal gas quenching according to the 1 st group orthogonal test scheme in the step 1 to obtain the 3 samples in the 1 st group after isothermal gas quenching.
And (3) selecting 3 original samples in the group 2, and carrying out isothermal gas quenching according to the orthogonal test scheme in the group 2 in the step 1 to obtain 3 isothermal gas quenched samples in the group 2.
And so on;
and (3) selecting 3 original samples in the 18 th group, and carrying out isothermal gas quenching according to the 18 th group orthogonal test scheme in the step 1 to obtain 3 isothermal gas quenched samples in the 18 th group.
And 4, respectively measuring the hardness of the 18 groups obtained in the step 3 and 3 isothermal gas quenching samples thereof according to the requirements of GB/T230.1-2004 Rockwell hardness test method:
selecting 7 points on the upper surface of a 1 st isothermal gas quenching sample of the first group to measure the hardness, wherein the hardness value of the 1 st isothermal gas quenching sample is the average value of 5 hardness values obtained by removing the maximum value and the minimum value; measuring to obtain the hardness values of the other 2 samples in the 1 st group; further, an average value H1 of the hardness of the sample after isothermal gas quenching of group 1, 3 blocks was obtained.
And so on;
the average value Hi of the hardness of the 3 isothermal gas-quenched samples in each group was obtained.
And 5, taking one of the 1 st group of samples subjected to isothermal gas quenching obtained in the step 4, carrying out linear cutting, processing the sample into four room-temperature impact test samples with the size of 10mm multiplied by 55mm, respectively carrying out room-temperature impact tests according to GB/T229-2007 metallic material Charpy pendulum impact test method, measuring the impact toughness of the four room-temperature impact test samples in the 1 st group, and obtaining the average value alpha k1 of the impact toughness of the four room-temperature impact test samples in the 1 st group.
And so on;
and obtaining the average value alpha ki of the impact toughness of each group of samples subjected to isothermal gas quenching.
And 6, firstly, taking one sample from each group of isothermal gas-quenched samples obtained in the step 4, carrying out linear cutting, processing the samples into wear samples, respectively carrying out room-temperature wear tests on a friction wear tester according to ASTM standard D:3702-94 (1999), and then measuring by adopting a weighing method to obtain the wear loss Mi of each group of wear samples.
And 7, according to the provisions of GB 228-2002 'Metal Material Room temperature tensile test method', respectively carrying out wire cutting on the last sample in each group of isothermal gas quenched samples obtained in the step 4, processing the samples into tensile samples with specified dimensions, and then sequentially carrying out tensile test to obtain the tensile strength YSi of each group of tensile samples.
Step 8, obtaining the comprehensive performance index delta i of the sample after isothermal gas quenching according to the Rockwell hardness Hi, the impact toughness alpha ki, the abrasion Mi and the tensile strength YSi which are measured in the steps 4 to 7
In formula (1):
hi represents the average value of the hardness of any group of samples after isothermal gas quenching, and the unit is HRC;
alpha ki represents the average value of the impact toughness of any group of samples after isothermal gas quenching, and the unit is J/cm 2 ；
Mi represents the abrasion loss of any group of samples after isothermal gas quenching, and the unit is mg;
YSi represents the tensile strength of any group of samples after isothermal gas quenching, and the unit is MPa;
and delta i represents the comprehensive performance index of any group of samples after isothermal gas quenching.
In steps 4 to 8, i represents the number of sample groups corresponding to any of the 18 orthogonal test patterns, and i is a natural number of 1 to 18.
And 9, selecting isothermal gas quenching process parameters corresponding to a group of test schemes with the maximum value of delta i from the comprehensive performance index delta i obtained in the step 8, and using the isothermal gas quenching process parameters as a basis for determining isothermal gas quenching process parameters of the cold-work die material in industrial production.
Example 1
1. A method for determining isothermal gas quenching process parameters for prolonging the service life of a cold-work die material. The method of the embodiment comprises the following steps:
in step 1, the material of the cold-work die in this embodiment is Cr12MoV. According to actual experience and the phase change curve of Cr12MoV cold-work die steel, selecting 5 factors of quenching temperature, heat preservation time, gas quenching pressure, isothermal temperature and isothermal time to carry out 3-level orthogonal test design, and establishing L shown in Table 1 18 (3 5 ) Orthogonal test table, obtaining 18 sets of orthogonal test schemes.
The ranges of the 5 process parameters: the quenching temperature is 950-1050 ℃; the heat preservation time is 10min to 40min; the gas quenching pressure is 3-9 bar; the isothermal temperature is 200-280 ℃; the isothermal time is 1-3 h.
Five factors and three levels were taken as: the quenching temperature is 950 ℃, 1000 ℃ and 1050 ℃; the heat preservation time is 10min, 25min and 40min; the gas quenching pressure is 3bar, 6bar and 9bar; isothermal temperature is 200 ℃, 240 ℃ and 280 ℃; the isothermal time is 1h, 2h and 3h.
TABLE 1L 18 (3 5 ) Orthogonal test table
And 2, selecting 18 x 3 Cr12MoV cold-work die materials produced in the same batch as 18 groups of original samples, wherein each group comprises 3 blocks. Each set of original samples: the length is 75mm; the width is 25mm; the height is 20mm.
And 3, selecting 3 original samples in the 1 st group, and carrying out isothermal gas quenching according to the 1 st group orthogonal test scheme in the 1 st group to obtain the 3 isothermal gas quenched samples in the 1 st group.
And (3) selecting 3 original samples in the group 2, and carrying out isothermal gas quenching according to the orthogonal test scheme in the group 2 in the step 1 to obtain 3 isothermal gas quenched samples in the group 2.
And so on;
and (3) selecting 3 original samples in the 18 th group, and carrying out isothermal gas quenching according to the 18 th group orthogonal test scheme in the step 1 to obtain 3 isothermal gas quenched samples in the 18 th group.
And 4, respectively measuring the hardness of the 18 groups obtained in the step 3 and 3 isothermal gas-quenched samples thereof according to the requirements of GB/T230.1-2004 Rockwell hardness test method:
selecting 7 points on the upper surface of a 1 st isothermal gas quenching sample of the first group to measure the hardness, wherein the hardness value of the 1 st isothermal gas quenching sample is the average value of 5 hardness values obtained by removing the maximum value and the minimum value; measuring to obtain the hardness values of the other 2 samples in the 1 st group; further, an average value H1 of the hardness of the sample after isothermal gas quenching of group 1, 3 blocks was obtained.
And so on;
the average value Hi of the hardness of each of the 3 isothermal gas-quenched samples shown in table 2 was obtained.
Table 2 average value Hi unit of hardness of 3 isothermal gas-quenched samples per group: HRC
And 5, taking one of the 1 st group of samples subjected to isothermal gas quenching obtained in the step 4, carrying out linear cutting, processing the sample into four room-temperature impact test samples with the size of 10mm multiplied by 55mm, respectively carrying out room-temperature impact tests according to GB/T229-2007 metallic material Charpy pendulum impact test method, measuring the impact toughness of the four room-temperature impact test samples in the 1 st group, and obtaining the average value alpha k1 of the impact toughness of the four room-temperature impact test samples in the 1 st group.
And so on;
the average value α ki of the impact toughness of each set of the isothermal gas-quenched samples was obtained as shown in table 3.
Table 3 average unit of impact toughness for each set of isothermal gas quenched samples: j/cm 2
And 6, firstly, taking one sample from each group of isothermal gas-quenched samples obtained in the step 4, carrying out linear cutting, processing the samples into wear samples with phi of 6 multiplied by 20, and then respectively carrying out room-temperature wear tests on a friction wear tester according to ASTM standard D:3702-94 (1999), wherein the abrasive material adopts 400-mesh water-milled sand paper and 20N external load, and the test duration is 10min. Then, the abrasion amount Mi of each abrasion sample group shown in table 4 was measured by weighing.
Table 4 abrasion amount Mi unit for each abrasion sample: mg of
And 7, respectively carrying out wire cutting on the last sample in each group of isothermal gas-quenched samples obtained in the step 4 according to the regulations in GB 228-2002 'Metal Material Room temperature tensile test method', processing the last sample into tensile samples with specified dimensions, and then sequentially carrying out tensile tests to obtain the tensile strength YSi of each group of tensile samples shown in Table 5.
Table 5 tensile strength YSi units for each set of tensile specimens: mpa (Mpa)
Step 8, obtaining the comprehensive performance index delta i of the sample subjected to isothermal gas quenching according to the Rockwell hardness Hi, the impact toughness alpha ki, the abrasion loss Mi and the tensile strength YSi which are measured in the steps 4 to 7
In formula (1):
hi represents the average value of the hardness of any group of samples after isothermal gas quenching, and the unit is HRC;
alpha ki represents the average value of the impact toughness of any group of samples after isothermal gas quenching, and the unit is J/cm 2 ；
Mi represents the abrasion loss of any group of samples after isothermal gas quenching, and the unit is mg;
YSi represents the tensile strength of any group of samples after isothermal gas quenching, and the unit is MPa;
and delta i represents the comprehensive performance index of any group of samples after isothermal gas quenching.
And (4) respectively bringing the average hardness Hi, the average impact toughness alphaki, the abrasion loss Mi and the tensile strength YSi which are sequentially obtained in the steps 4, 5, 6 and 7 into the formula (1) to obtain the comprehensive performance indexes of each group of samples shown in the table 6.
TABLE 6 comprehensive performance index of each group of samples
In steps 4 to 8, i represents the number of sample groups corresponding to any of the 18 orthogonal test patterns, and i is a natural number of 1 to 18.
Step 9, selecting isothermal gas quenching process parameters corresponding to a group of test schemes with the largest δ i value from the comprehensive performance indexes δ i obtained in the table 6 in the step 8, namely the optimal isothermal gas quenching process parameters of the Cr12MoV cold-work die material corresponding to the test scheme 9 are as follows: the quenching temperature is 1050 ℃, the heat preservation time is 40min, the gas quenching pressure is 3bar, the isothermal temperature is 280 ℃, and the isothermal time is 2h, and the isothermal gas quenching temperature are taken as the basis for determining the isothermal gas quenching process parameters of the cold-work die material in industrial production.
Example 2
1. A method for determining isothermal gas quenching process parameters for prolonging the service life of a cold-work die material. The method of the embodiment comprises the following steps:
in step 1, the material of the cold-work die shown in this embodiment is SKD11. According to actual experience and a phase transition curve of SKD11 cold-work die steel, selecting 5 factors of quenching temperature, heat preservation time, gas quenching pressure, isothermal temperature and isothermal time to carry out 3-level orthogonal test design, and establishing L shown in table 1 18 (3 5 ) And (4) obtaining 18 groups of orthogonal test schemes.
The ranges of the 5 process parameters: the quenching temperature is 950-1050 ℃; the heat preservation time is 10min to 40min; the gas quenching pressure is 3-9 bar; the isothermal temperature is 200-280 ℃; the isothermal time is 1 h-3 h;
five factors and three levels were taken as: the quenching temperature is 950 ℃, 1000 ℃ and 1050 ℃; the heat preservation time is 10min, 25min and 40min; the gas quenching pressure is 3bar, 6bar and 9bar; isothermal temperature is 200 ℃, 240 ℃ and 280 ℃; the isothermal time is 1h, 2h and 3h.
TABLE 1L 18 (3 5 ) Orthogonal test table
And 2, selecting 18 x 3 SKD11 cold-work die materials produced in the same batch as 18 groups of original samples, wherein each group comprises 3 blocks. The original sample: the length is 75mm; the width is 25mm; the height is 20mm.
And 3, selecting 3 original samples in the 1 st group, and carrying out isothermal gas quenching according to the 1 st group orthogonal test scheme in the 1 st group to obtain the 3 isothermal gas quenched samples in the 1 st group.
And (3) selecting 3 original samples in the group 2, and carrying out isothermal gas quenching according to the orthogonal test scheme in the group 2 in the step 1 to obtain 3 isothermal gas quenched samples in the group 2.
And so on;
and (3) selecting 3 original samples in the 18 th group, and carrying out isothermal gas quenching according to the 18 th group orthogonal test scheme in the step 1 to obtain 3 isothermal gas quenched samples in the 18 th group.
And 4, respectively measuring the hardness of the 18 groups obtained in the step 3 and 3 isothermal gas-quenched samples thereof according to the requirements of GB/T230.1-2004 Rockwell hardness test method:
selecting 7 points on the upper surface of the 1 st isothermal gas-quenched sample of the first group to measure the hardness, wherein the hardness value of the 1 st isothermal gas-quenched sample is the average value of 5 hardness values obtained by removing the maximum value and the minimum value; measuring to obtain the hardness values of the other 2 samples in the 1 st group; further, an average value H1 of the hardness of the sample after isothermal gas quenching of group 1, 3 blocks was obtained.
And so on;
the average value Hi of the hardness of each of the 3 isothermal gas-quenched samples shown in table 2 was obtained.
Table 2 average value Hi unit of hardness of 3 isothermal gas-quenched samples per group: HRC
And 5, taking one of the 1 st group of samples subjected to isothermal gas quenching obtained in the step 4, carrying out linear cutting, processing the sample into four room-temperature impact test samples with the size of 10mm multiplied by 55mm, respectively carrying out room-temperature impact tests according to GB/T229-2007 metallic material Charpy pendulum impact test method, measuring the impact toughness of the four room-temperature impact test samples in the 1 st group, and obtaining the average value alpha k1 of the impact toughness of the four room-temperature impact test samples in the 1 st group.
And so on;
the average value α ki of the impact toughness of each set of the isothermally gas-quenched samples was obtained as shown in table 3.
Table 3 average unit of impact toughness of each group of isothermal gas quenched samples: j/cm 2
And step 6, respectively taking one sample from each group of isothermal gas-quenched samples obtained in the step 4, carrying out linear cutting, processing the samples into wear samples with phi of 6 multiplied by 20, and respectively carrying out room-temperature wear tests on a friction wear testing machine according to an ASTM standard D:3702-94 (1999), wherein the grinding materials adopt 400-mesh water-grinding abrasive paper and 20N external load, and the test time is 10min. Then, the abrasion amount Mi of each abrasion sample was measured by weighing method as shown in table 4.
Table 4 abrasion amount Mi units per abrasion sample: mg of
And 7, according to the regulations in GB 228-2002 'Metal Material Room temperature tensile test method', respectively carrying out wire cutting on the last sample in each group of isothermal gas quenched samples obtained in the step 4, processing the last sample into tensile samples with specified dimensions, and then sequentially carrying out tensile tests to obtain the tensile strength YSi of each group of tensile samples shown in the table 5.
Table 5 tensile strength YSi units for each set of tensile specimens: mpa (Mpa)
Step 8, obtaining the comprehensive performance index delta i of the sample after isothermal gas quenching according to the Rockwell hardness Hi, the impact toughness alpha ki, the abrasion Mi and the tensile strength YSi which are measured in the steps 4 to 7
In formula (1):
hi represents the average value of the hardness of any group of samples after isothermal gas quenching, and the unit is HRC;
alpha ki represents the average value of the impact toughness of any group of samples after isothermal gas quenching, and the unit is J/cm 2 ；
Mi represents the abrasion loss of any group of samples after isothermal gas quenching, and the unit is mg;
YSi represents the tensile strength of any group of samples after isothermal gas quenching, and the unit is MPa;
and delta i represents the comprehensive performance index of any group of samples after isothermal gas quenching.
And (3) respectively driving the average hardness Hi, the average impact toughness alpha ki, the abrasion loss Mi and the tensile strength YSi which are sequentially obtained in the steps 4, 5, 6 and 7 into the formula (1), so as to obtain the comprehensive performance indexes of each group of samples shown in the table 6.
TABLE 6 comprehensive performance index of each group of samples
In steps 4 to 8, i represents the number of sample groups corresponding to any of the 18 orthogonal test patterns, and i is a natural number of 1 to 18.
Step 9, selecting a group of isothermal gas quenching process parameters corresponding to the test scheme with the largest δ i value from the comprehensive performance index δ i obtained in the table 6 of the step 8, namely the optimum process parameters of isothermal gas quenching of the SKD11 cold work die material corresponding to the test scheme 15 are as follows: the quenching temperature is 1000 ℃, the heat preservation time is 40min, the gas quenching pressure is 3bar, the isothermal temperature is 240 ℃ and the isothermal time is 3h, and the isothermal gas quenching temperature are used as the basis for determining the isothermal gas quenching process parameters of the cold-work die material in industrial production.
Compared with the prior art, the specific implementation mode has the following positive effects:
1. the specific embodiment determines the ranges of quenching temperature, holding time, gas quenching pressure, isothermal temperature and isothermal time, performs orthogonal test design according to 5-factor-3 level, and establishes L 18 (3 5 ) The method comprises the steps of performing isothermal gas quenching according to a set test scheme, then performing hardness test, room temperature impact test, wear resistance test and tensile test on each group of isothermal gas quenched samples to obtain a comprehensive performance index delta i of the isothermal gas quenched samples, comparing the delta i values, selecting isothermal gas quenching process parameters corresponding to a group of test schemes with the largest delta i value to serve as a basis for determining isothermal gas quenching process parameters of cold-work die materials in industrial production, and is suitable for determining isothermal gas quenching process parameters of various cold-work die materials, so that the performance of the cold-work die materials can be improved, and the service life of the cold-work die materials can be prolonged.
2. The specific embodiment reasonably configures 5 process parameters of isothermal gas quenching of the cold-work die material, and performs isothermal gas quenching treatment on the cold-work die material under the process parameters, and the test result shows that: hardness, impact toughness, wearability, tensile strength of mould material all promote, find the intensive degree of dimple wherein and improve after detecting the fracture of steel, observe through scanning electron microscope picture: compared with the conventional heat treatment, the cold-work die material obtained after isothermal gas quenching is carried out by adopting the process parameters determined by the specific embodiment is shown in the attached drawing, and fig. 1 is a scanning electron microscope image of the cold-work die steel after isothermal gas quenching carried out by adopting the process parameters determined by the embodiment 1; FIG. 2 is a scanning electron microscope image of cold work die steel after conventional heat treatment. From a comparison of fig. 1 and 2, it can be seen that: the strip-shaped carbides of the cold work die steel shown in fig. 1 disappear, the carbides are uniformly distributed, and the metal grains are finer. Therefore, the process parameters determined by the specific embodiment can improve the performance of the quenched cold-work die material, thereby prolonging the service life of the die.
Therefore, the method is suitable for determining the isothermal gas quenching process parameters of various cold-work die materials, and the determined process parameters can be used as the basis for determining the isothermal gas quenching process parameters of the cold-work die materials in industrial production, so that the performance and the service life of the cold-work die materials can be improved.
Claims (1)
1. A method for determining isothermal gas quenching process parameters for prolonging the service life of a cold-work die material is characterized by comprising the following steps:
step 1, selecting 5 factors of quenching temperature, heat preservation time, gas quenching pressure, isothermal temperature and isothermal time to carry out 3-level orthogonal test design, and establishing L 18 (3 5 ) Obtaining 18 groups of orthogonal test schemes;
the ranges of the 5 process parameters: the quenching temperature is 950-1050 ℃, the heat preservation time is 10-40 min, the gas quenching pressure is 3-9 bar, the isothermal temperature is 200-280 ℃, and the isothermal time is 1-3 h;
step 2, selecting 18 x 3 blocks of cold-work die materials produced in the same batch as 18 groups of original samples, wherein each group comprises 3 blocks;
step 3, selecting 3 original samples in the group 1, and carrying out isothermal gas quenching according to the orthogonal test scheme in the group 1 in the step 1 to obtain 3 samples in the group 1 after isothermal gas quenching;
selecting 3 original samples in the group 2, and carrying out isothermal gas quenching according to the orthogonal test scheme in the group 2 in the step 1 to obtain 3 isothermal gas quenched samples in the group 2;
and so on;
selecting 3 original samples in the 18 th group, and carrying out isothermal gas quenching according to the 18 th group orthogonal test scheme in the step 1 to obtain 3 isothermal gas quenched samples in the 18 th group;
and 4, respectively measuring the hardness of the 18 groups obtained in the step 3 and 3 isothermal gas quenching samples thereof according to the requirements of GB/T230.1-2004 Rockwell hardness test method:
selecting 7 points on the upper surface of the 1 st isothermal gas-quenched sample of the first group to measure the hardness, wherein the hardness value of the 1 st isothermal gas-quenched sample is the average value of 5 hardness values obtained by removing the maximum value and the minimum value; measuring to obtain the hardness values of the other 2 samples in the 1 st group; further, obtaining an average value H1 of the hardness of the group 1 3 isothermal gas quenched samples;
and so on;
obtaining the average value Hi of the hardness of each group of 3 isothermal gas-quenched samples;
step 5, taking one of the samples obtained from the group 1 after isothermal gas quenching in the step 4, carrying out linear cutting, processing the sample into four room temperature impact test samples with the size of 10mm multiplied by 55mm, respectively carrying out room temperature impact tests according to GB/T229-2007 metallic material Charpy pendulum impact test method, measuring the impact toughness of the four room temperature impact test samples in the group 1, and obtaining the average value alpha k1 of the impact toughness of the four room temperature impact test samples in the group 1;
and so on;
obtaining the average value alpha ki of the impact toughness of each group of samples subjected to isothermal gas quenching;
step 6, respectively taking a sample from each group of isothermal gas-quenched samples obtained in the step 4, carrying out linear cutting, processing the samples into wear samples, respectively carrying out room-temperature wear tests on a friction wear tester according to an ASTM standard D:3702-94 (1999), and measuring by adopting a weighing method to obtain the wear amount Mi of each group of wear samples;
step 7, according to the provisions of GB 228-2002 metal material room temperature tensile test method, respectively carrying out wire cutting on the last sample in each group of isothermal gas-quenched samples obtained in the step 4, processing the samples into tensile samples with the prescribed size, and then sequentially carrying out tensile test to obtain the tensile strength YSi of each group of tensile samples;
step 8, obtaining the comprehensive performance index delta i of the sample after isothermal gas quenching according to the Rockwell hardness Hi, the impact toughness alpha ki, the abrasion Mi and the tensile strength YSi which are measured in the steps 4 to 7
In formula (1):
hi represents the average value of the hardness of any group of samples after isothermal gas quenching, and the unit is HRC,
alpha ki represents the average value of the impact toughness of any group of samples after isothermal gas quenching, and the unit is J/cm 2 ，
Mi represents the abrasion loss of any group of samples after isothermal gas quenching, and the unit is mg,
YSi represents the tensile strength of any group of samples after isothermal gas quenching, and the unit is MPa,
delta i represents the comprehensive performance index of any group of samples after isothermal gas quenching;
in steps 4 to 8, i represents the serial number of the sample group corresponding to any one of 18 groups of orthogonal test schemes, and i is a natural number from 1 to 18;
and 9, selecting isothermal gas quenching process parameters corresponding to a group of test schemes with the largest delta i value from the comprehensive performance indexes delta i obtained in the step 8, and using the isothermal gas quenching process parameters as a basis for determining isothermal gas quenching process parameters of the cold-work die material in industrial production.
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Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01198422A (en) * | 1988-02-02 | 1989-08-10 | Idemitsu Kosan Co Ltd | Method for deciding heat treating condition of metal material |
| CN103886371A (en) * | 2014-03-28 | 2014-06-25 | 郑州大学 | Method for controlling component and thermal treatment technological process of pre-hardening plastic die steel |
| CN106367566A (en) * | 2016-09-14 | 2017-02-01 | 安徽工程大学 | Method for testing performance of Cr12 die steel for stamping die |
| CN107287400A (en) * | 2016-08-05 | 2017-10-24 | 中国科学院金属研究所 | A kind of method of the pre- hard plastic mould steel temperatures of determination 718H |
| CN110205480A (en) * | 2019-07-08 | 2019-09-06 | 沈阳中金模具钢有限公司 | A kind of testing experiment method reducing heat-treatment distortion optimization heat treatment process |
| RU2760634C1 (en) * | 2020-11-03 | 2021-11-29 | Федеральное государственное бюджетное учреждение науки Институт физики металлов имени М.Н. Михеева Уральского отделения Российской академии наук (ИФМ УрО РАН) | Method for estimating the impact strength of products made of bainitically quenched construction steel |
-
2022
- 2022-08-04 CN CN202210934299.2A patent/CN115449607B/en active Active
Patent Citations (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPH01198422A (en) * | 1988-02-02 | 1989-08-10 | Idemitsu Kosan Co Ltd | Method for deciding heat treating condition of metal material |
| CN103886371A (en) * | 2014-03-28 | 2014-06-25 | 郑州大学 | Method for controlling component and thermal treatment technological process of pre-hardening plastic die steel |
| CN107287400A (en) * | 2016-08-05 | 2017-10-24 | 中国科学院金属研究所 | A kind of method of the pre- hard plastic mould steel temperatures of determination 718H |
| CN106367566A (en) * | 2016-09-14 | 2017-02-01 | 安徽工程大学 | Method for testing performance of Cr12 die steel for stamping die |
| CN110205480A (en) * | 2019-07-08 | 2019-09-06 | 沈阳中金模具钢有限公司 | A kind of testing experiment method reducing heat-treatment distortion optimization heat treatment process |
| RU2760634C1 (en) * | 2020-11-03 | 2021-11-29 | Федеральное государственное бюджетное учреждение науки Институт физики металлов имени М.Н. Михеева Уральского отделения Российской академии наук (ИФМ УрО РАН) | Method for estimating the impact strength of products made of bainitically quenched construction steel |
Non-Patent Citations (2)
| Title |
|---|
| 狄洪亮;张心明;: "半导体激光器抛光1.2333模具钢工艺参数优化研究", 兵器材料科学与工程, no. 02, pages 43 - 47 * |
| 王洪;郭旭红;王伟;: "等温淬火球铁热处理工艺参数的优化方法", 兵工学报, no. 01, pages 65 - 70 * |
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