Alloy steel forge piece and heat treatment method thereof
Through specific heat treatment methods, including step-by-step heating and insulation steps, combined with quenching and tempering treatment, the problem of insufficient mechanical properties of 30Cr3Mo steel is solved, and its yield strength and tensile strength are significantly improved.
Patent Information
- Application Number
- CN202510781003.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-12
- Publication Date
- 2025-08-19
AI Technical Summary
The existing heat treatment process of 30Cr3Mo steel has not been able to fully improve its mechanical properties, resulting in shortcomings in high strength, high toughness and wear resistance.
Specific heat treatment methods are adopted, including stepwise heating and insulation steps, combined with quenching and tempering treatment, and specific process parameters are controlled to improve the grain size and release internal stress of alloy steel forgings.
The yield strength and tensile strength of alloy steel forgings have been significantly improved, so that their yield strength is not less than 823MPa and the tensile strength is not less than 986MPa, which improves the mechanical properties of alloy steel forgings.
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of alloy steel, and in particular to an alloy steel forging and a heat treatment method thereof. Background Art
[0002] Alloy steel is steel that has other alloying elements in addition to iron and carbon. It's an iron-carbon alloy formed by adding appropriate amounts of one or more alloying elements to ordinary carbon steel. Depending on the added elements and appropriate processing techniques, special properties such as high strength, high toughness, wear resistance, corrosion resistance, low-temperature resistance, high-temperature resistance, and non-magnetic properties can be achieved.
[0003] 30Cr3Mo steel is an alloy structural steel with high strength, high toughness, and excellent wear and fatigue resistance. It is widely used in the manufacture of important components such as shafts, gears, and molds. 30Cr3Mo steel contains high levels of carbon, chromium, and molybdenum, which give it excellent hardenability and hardenability. However, different heat treatment processes result in different mechanical properties for 30Cr3Mo steel. Therefore, a heat treatment process is needed to better improve the mechanical properties of 30Cr3Mo steel. Summary of the Invention
[0004] The object of the present invention is to provide an alloy steel forging and a heat treatment method thereof. The heat treatment method of the present invention can better improve the mechanical properties of the alloy steel forging by controlling specific processes and parameters.
[0005] In order to achieve the above-mentioned purpose of the present invention, the following technical solutions are adopted:
[0006] A first aspect of the present invention provides a heat treatment method for an alloy steel forging, the heat treatment method for an alloy steel forging comprising the following steps:
[0007] (1) Heating the 30Cr3Mo alloy steel forgings to 280-300°C at 2-2.5°C / min and holding for 1-2 hours, then heating to 610-630°C at 3-4°C / min and holding for 2-3 hours; then heating to 900-910°C at 1-2°C / min and holding for 5-7 hours;
[0008] (2) placing the 30Cr3Mo alloy steel forging into the quenching liquid for cooling;
[0009] (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 300-350°C at a rate of 1-1.5°C / min and keep it at that temperature for 8-10 hours, then heat it to 580-600°C at a rate of 0.5-1°C / min and keep it at that temperature for 20-25 hours;
[0010] (4) Adjust the tempering furnace temperature to 350-380°C. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
[0011] Preferably, in step (1), the 30Cr3Mo alloy steel forging is heated to 290°C at a rate of 2.2°C / min and kept warm for 1.5 hours, then heated to 620°C at a rate of 3.5°C / min and kept warm for 2.5 hours; then heated to 905°C at a rate of 1.5°C / min and kept warm for 6 hours.
[0012] Preferably, in step (2), the quenching liquid is water or oil.
[0013] Preferably, in step (2), the temperature is cooled to below 100°C.
[0014] Preferably, in step (3), the 30Cr3Mo alloy steel forging is placed in a tempering furnace and heated to 330°C at a rate of 1.2°C / min and kept warm for 9 hours, and then heated to 590°C at a rate of 0.8°C / min and kept warm for 22 hours.
[0015] Preferably, in step (4), the tempering furnace temperature is adjusted to 370°C.
[0016] A second aspect of the present invention provides an alloy steel forging obtained by the above alloy steel forging heat treatment method.
[0017] Preferably, the yield strength of the alloy steel forging is not less than 823 MPa, and the tensile strength is not less than 986 MPa.
[0018] Compared with the prior art, the beneficial effects of the present invention include at least:
[0019] The heat treatment method of the present invention can better improve the grain size of the alloy steel forging and fully release the internal stress through the control of specific processes and parameters, thereby better improving the mechanical properties of the alloy steel forging. DETAILED DESCRIPTION
[0020] The following embodiments of the technical solution of the present invention are described in detail in conjunction with the embodiments. The following embodiments are only used to more clearly illustrate the technical solution of the present invention and are therefore only used as examples and cannot be used to limit the scope of protection of the present invention.
[0021] It should be noted that, unless otherwise specified, the technical or scientific terms used in this application should have the common meanings understood by those skilled in the art to which the present invention belongs.
[0022] An embodiment of the present invention provides a heat treatment method for an alloy steel forging, the heat treatment method for an alloy steel forging comprising the following steps:
[0023] (1) Heating the 30Cr3Mo alloy steel forgings to 280-300°C at 2-2.5°C / min and holding for 1-2 hours, then heating to 610-630°C at 3-4°C / min and holding for 2-3 hours; then heating to 900-910°C at 1-2°C / min and holding for 5-7 hours;
[0024] (2) placing the 30Cr3Mo alloy steel forging into the quenching liquid for cooling;
[0025] (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 300-350°C at a rate of 1-1.5°C / min and keep it at that temperature for 8-10 hours, then heat it to 580-600°C at a rate of 0.5-1°C / min and keep it at that temperature for 20-25 hours;
[0026] (4) Adjust the tempering furnace temperature to 350-380°C. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
[0027] The heat treatment method of the present invention can better improve the grain size of the alloy steel forging and fully release the internal stress through the control of specific processes and parameters, thereby better improving the mechanical properties of the alloy steel forging.
[0028] In one embodiment, in step (1), the 30Cr3Mo alloy steel forging is heated to 290°C at a rate of 2.2°C / min and kept at that temperature for 1.5 hours, then heated to 620°C at a rate of 3.5°C / min and kept at that temperature for 2.5 hours; then heated to 905°C at a rate of 1.5°C / min and kept at that temperature for 6 hours.
[0029] In one embodiment, in step (2), the quenching liquid is water or oil.
[0030] In one embodiment, in step (2), the temperature is cooled to below 100°C.
[0031] In one embodiment, in step (3), the 30Cr3Mo alloy steel forging is placed in a tempering furnace and heated to 330°C at a rate of 1.2°C / min and kept at that temperature for 9 hours, and then heated to 590°C at a rate of 0.8°C / min and kept at that temperature for 22 hours.
[0032] In one embodiment, in step (4), the tempering furnace temperature is adjusted to 370°C.
[0033] Another embodiment of the present invention provides an alloy steel forging obtained by the above alloy steel forging heat treatment method.
[0034] In one embodiment, the alloy steel forging has a yield strength of not less than 823 MPa and a tensile strength of not less than 986 MPa.
[0035] The technical solution of the present invention is further described in detail below through specific embodiments.
[0036] Example 1
[0037] This embodiment provides a heat treatment method for alloy steel forgings, which includes the following steps:
[0038] (1) The 30Cr3Mo alloy steel forging was heated to 280°C at 2°C / min and kept at this temperature for 2 h, then heated to 610°C at 4°C / min and kept at this temperature for 3 h; then heated to 900°C at 1°C / min and kept at this temperature for 7 h;
[0039] (2) placing the 30Cr3Mo alloy steel forging into the quenching liquid for cooling;
[0040] (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 350°C at 1°C / min and keep it at that temperature for 8 hours, then heat it to 600°C at 0.5°C / min and keep it at that temperature for 20 hours;
[0041] (4) Adjust the tempering furnace temperature to 350℃. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
[0042] Example 2
[0043] This embodiment provides a heat treatment method for alloy steel forgings, which includes the following steps:
[0044] (1) The 30Cr3Mo alloy steel forging was heated to 300°C at 2.5°C / min and kept at this temperature for 1 hour. Then, the temperature was increased to 630°C at 3°C / min and kept at this temperature for 2-3 hours. The temperature was then increased to 910°C at 2°C / min and kept at this temperature for 5 hours.
[0045] (2) placing the 30Cr3Mo alloy steel forging into the quenching liquid for cooling;
[0046] (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 300°C at a rate of 1.5°C / min and keep it at that temperature for 10 h, then heat it to 580°C at a rate of 1°C / min and keep it at that temperature for 25 h;
[0047] (4) Adjust the tempering furnace temperature to 380℃. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
[0048] Example 3
[0049] This embodiment provides a heat treatment method for alloy steel forgings, which includes the following steps:
[0050] (1) The 30Cr3Mo alloy steel forging was heated to 290°C at 2.2°C / min and kept at this temperature for 1.5 h. Then, the temperature was increased to 620°C at 3.5°C / min and kept at this temperature for 2.5 h. The temperature was then increased to 905°C at 1.5°C / min and kept at this temperature for 6 h.
[0051] (2) Place the 30Cr3Mo alloy steel forging in water and cool it to below 100°C;
[0052] (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 330°C at a rate of 1.2°C / min and keep it at that temperature for 9 hours, then heat it to 590°C at a rate of 0.8°C / min and keep it at that temperature for 22 hours;
[0053] (4) Adjust the tempering furnace temperature to 370℃. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
[0054] Comparative Example 1
[0055] This comparative example is a heat treatment method for alloy steel forgings, which comprises the following steps:
[0056] (1) The 30Cr3Mo alloy steel forging was heated to 620°C at 3.5°C / min and kept at this temperature for 4 h; then heated to 905°C at 1.5°C / min and kept at this temperature for 6 h;
[0057] (2) Place the 30Cr3Mo alloy steel forging in water and cool it to below 100°C;
[0058] (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 330°C at a rate of 1.2°C / min and keep it at that temperature for 9 hours, then heat it to 590°C at a rate of 0.8°C / min and keep it at that temperature for 22 hours;
[0059] (4) Adjust the tempering furnace temperature to 370℃. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
[0060] Comparative Example 2
[0061] This comparative example is a heat treatment method for alloy steel forgings, which comprises the following steps:
[0062] (1) The 30Cr3Mo alloy steel forging was heated at 2.2°C / min to 905°C and kept at this temperature for 10 h;
[0063] (2) Place the 30Cr3Mo alloy steel forging in water and cool it to below 100°C;
[0064] (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 330°C at a rate of 1.2°C / min and keep it at that temperature for 9 hours, then heat it to 590°C at a rate of 0.8°C / min and keep it at that temperature for 22 hours;
[0065] (4) Adjust the tempering furnace temperature to 370℃. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
[0066] Comparative Example 3
[0067] This comparative example is a heat treatment method for alloy steel forgings, which comprises the following steps:
[0068] (1) The 30Cr3Mo alloy steel forging was heated to 290°C at 2.2°C / min and kept at this temperature for 1.5 h. Then, the temperature was increased to 620°C at 2.2°C / min and kept at this temperature for 2.5 h. The temperature was then increased to 905°C at 1.5°C / min and kept at this temperature for 6 h.
[0069] (2) Place the 30Cr3Mo alloy steel forging in water and cool it to below 100°C;
[0070] (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 330°C at a rate of 1.2°C / min and keep it at that temperature for 9 hours, then heat it to 590°C at a rate of 0.8°C / min and keep it at that temperature for 22 hours;
[0071] (4) Adjust the tempering furnace temperature to 370℃. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
[0072] Comparative Example 4
[0073] This comparative example is a heat treatment method for alloy steel forgings, which comprises the following steps:
[0074] (1) The 30Cr3Mo alloy steel forging was heated to 290°C at 2.2°C / min and kept at this temperature for 1.5 h. Then, the temperature was increased to 620°C at 3.5°C / min and kept at this temperature for 2.5 h. The temperature was then increased to 905°C at 1.5°C / min and kept at this temperature for 6 h.
[0075] (2) Place the 30Cr3Mo alloy steel forging in water and cool it to below 100°C;
[0076] (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 590°C at a rate of 1.2°C / min and keep it at that temperature for 31 hours;
[0077] (4) Adjust the tempering furnace temperature to 370℃. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
[0078] Comparative Example 5
[0079] This comparative example is a heat treatment method for alloy steel forgings, which comprises the following steps:
[0080] (1) The 30Cr3Mo alloy steel forging was heated to 290°C at 2.2°C / min and kept at this temperature for 1.5 h. Then, the temperature was increased to 620°C at 3.5°C / min and kept at this temperature for 2.5 h. The temperature was then increased to 905°C at 1.5°C / min and kept at this temperature for 6 h.
[0081] (2) Place the 30Cr3Mo alloy steel forging in water and cool it to below 100°C;
[0082] (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 330°C at a rate of 1.2°C / min and keep it at that temperature for 9 hours, then heat it to 610°C at a rate of 0.8°C / min and keep it at that temperature for 22 hours;
[0083] (4) Adjust the tempering furnace temperature to 370℃. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
[0084] Experimental example
[0085] The alloy steel forgings prepared in Examples 1 to 3 and Comparative Examples 1 to 5 were obtained respectively;
[0086] The yield strength and tensile strength of the above alloy steel forgings were tested, and the test results are shown in Table 1:
[0087] Table 1
[0088] Group Yield strength (MPa) Tensile strength (MPa) Example 1 823 994 Example 2 832 986 Example 3 857 1051 Comparative Example 1 741 923 Comparative Example 2 718 897 Comparative Example 3 805 953 Comparative Example 4 816 947 Comparative Example 5 787 921
[0089] From Table 1 we can see that:
[0090] Compared with the comparative example, the alloy steel forgings prepared in the examples of the present application have more excellent mechanical properties.
[0091] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the above embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the above embodiments, or make equivalent replacements for some or all of the technical features therein. These modifications or replacements do not deviate the essence of the corresponding technical solutions from the scope of the technical solutions of the embodiments of the present invention, and they should all be included in the scope of the claims and description of the present invention.
Claims
1. A heat treatment method for alloy steel forgings, characterized in that: The alloy steel forging heat treatment method comprises the following steps: (1) Heating the 30Cr3Mo alloy steel forgings to 280-300°C at 2-2.5°C / min and holding for 1-2 hours, then heating to 610-630°C at 3-4°C / min and holding for 2-3 hours; then heating to 900-910°C at 1-2°C / min and holding for 5-7 hours; (2) placing the 30Cr3Mo alloy steel forging into the quenching liquid for cooling; (3) Place the 30Cr3Mo alloy steel forging in a tempering furnace and heat it to 300-350°C at a rate of 1-1.5°C / min and keep it at that temperature for 8-10 hours, then heat it to 580-600°C at a rate of 0.5-1°C / min and keep it at that temperature for 20-25 hours; (4) Adjust the tempering furnace temperature to 350-380°C. When the 30Cr3Mo alloy steel forgings cool down to the tempering furnace temperature, take them out and let them cool naturally.
2. The alloy steel forging heat treatment method according to claim 1, characterized in that: In the step (1), the 30Cr3Mo alloy steel forging is heated to 290°C at a rate of 2.2°C / min and kept warm for 1.5 hours, then heated to 620°C at a rate of 3.5°C / min and kept warm for 2.5 hours; and then heated to 905°C at a rate of 1.5°C / min and kept warm for 6 hours.
3. The heat treatment method for alloy steel forgings according to claim 1, characterized in that: In the step (2), the quenching liquid is water or oil.
4. The alloy steel forging heat treatment method according to claim 1, characterized in that: In the step (2), the temperature is cooled to below 100°C.
5. The alloy steel forging heat treatment method according to claim 1, characterized in that: In the step (3), the 30Cr3Mo alloy steel forging is placed in a tempering furnace, heated to 330°C at a rate of 1.2°C / min and kept warm for 9 hours, and then heated to 590°C at a rate of 0.8°C / min and kept warm for 22 hours.
6. The alloy steel forging heat treatment method according to claim 1, characterized in that: In the step (4), the tempering furnace temperature is adjusted to 370°C.
7. An alloy steel forging obtained by the alloy steel forging heat treatment method according to any one of claims 1 to 6.
8. The alloy steel forging according to claim 7, characterized in that: The yield strength of the alloy steel forging is not less than 823 MPa, and the tensile strength is not less than 986 MPa.