A GH4080A alloy and a heat treatment method to improve impact energy

Abstract

This invention provides a heat treatment method for improving the impact energy of GH4080A alloy, comprising the following steps: S1: Selecting GH4080A alloy material for which impact energy needs to be improved, and subjecting it to solution treatment; S2: Placing the GH4080A alloy treated in step S1 into an electric heating furnace for aging treatment at a temperature of 650℃-750℃ for 9-11 hours; S3: Cooling the GH4080A alloy after the aging treatment in step S2 to complete the heat treatment. This invention solves the problem that GH4080A alloy prepared by conventional heat treatment methods has low impact energy, failing to meet technical standards, and has high commercial and promotional value.

Description

Technical Field

[0001] This invention relates to the field of high-temperature alloy heat treatment, and more specifically, to a GH4080A alloy and a heat treatment method for improving impact energy. Background Technology

[0002] GH4080A is an age-hardening nickel-based superalloy, primarily strengthened by the addition of Al and Ti elements to form the γ' phase with Ni. It exhibits excellent oxidation and creep resistance within the 650-850℃ range and is used in the manufacture of exhaust valves for automotive and marine diesel engines. For diesel engine exhaust valves, this alloy requires a vacuum induction + electroslag remelting process, and the product is round bar, delivered in a solution-treated, bright silver state.

[0003] One of the performance requirements for GH4080A is that the impact energy Akv2 after solution treatment and aging heat treatment should be ≥35J, and the aging treatment temperature should be 700±10℃. The holding time for aging heat treatment is not specified. The impact energy of Φ28mm round silver bright material produced by conventional technology after solution treatment and aging treatment is 31.2J and 32.6J respectively, with an average value of 31.9J, which is lower than the standard requirement and cannot be delivered.

[0004] Therefore, there is an urgent need to propose a heat treatment method for GH4080A alloy and to improve its impact energy. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide a heat treatment method for improving the impact energy of GH4080A alloy, so as to solve the problem that the impact energy of GH4080A alloy prepared by conventional heat treatment methods is low and cannot meet the technical standard requirements.

[0006] To address the above problems, this invention provides a heat treatment method for improving the impact energy of GH4080A alloy, comprising the following steps:

[0007] S1: Select the GH4080A alloy to be improved, and put the GH4080A alloy sample into an electric heating furnace for solution treatment: heat up to 1020-1050℃, hold at this temperature for 1-2 hours, and then cool the sample to room temperature with water after taking it out of the furnace.

[0008] S2: The GH4080A alloy treated in step S1 is placed in an electric heating furnace for aging treatment. The holding temperature of the aging treatment is 650-750℃ and the holding time is 9-11h.

[0009] S3: After the aging treatment in step S2 is completed, the GH4080A alloy is taken out of the furnace and air-cooled to room temperature to complete the heat treatment.

[0010] As a preferred embodiment, in step S1, the GH4080A alloy comprises the following components:

[0011] C: 0.04%~0.10%; Si: ≤1.0%; Mn: ≤1.0%; S: ≤0.015%; P: ≤0.02%;

[0012] Cr: 18.0%–21.0%; Al: 1.0%–1.8%; Ti: 1.8%–2.7%; B: ≤0.008%; Co: ≤2.0%; Fe: ≤1.5%; Cu: ≤0.2%; balance is nickel and other unavoidable impurities.

[0013] As a preferred embodiment, the GH4080A alloy comprises the following components:

[0014] C: 0.05%; Si: ≤0.50%; Mn: ≤0.50%; S: ≤0.010%; P: ≤0.010%;

[0015] Cr: 20.0%; Al: 1.2%; Ti: 2.2%; B: ≤0.005%; Co: ≤1.0%; Fe: ≤1.0%; Cu: ≤0.2%; balance is nickel and other unavoidable impurities.

[0016] As a preferred embodiment, in step S1, the conditions for the solution treatment are: a holding temperature of 1025℃ and a holding time of 1 hour. The sample is then cooled to room temperature with water after being removed from the furnace.

[0017] As a preferred embodiment, in step S2, the aging treatment temperature is 700℃ and the holding time is 10h.

[0018] As a preferred embodiment, in step S3, the cooling condition is air cooling.

[0019] Another technical problem that this invention aims to solve is to provide a GH4080A alloy to address the issue of insufficient impact energy in conventional GH4080A alloys.

[0020] To address the aforementioned problems, this invention provides a GH4080A alloy, which is prepared by the heat treatment method described above.

[0021] As a preferred embodiment, the impact energy of the GH4080A alloy is greater than 35J.

[0022] Compared with the prior art, the present invention has the following technical advantages:

[0023] This invention controls the composition of GH4080A alloy, as well as the conditions of solution treatment and aging treatment, and keeps the temperature and time of aging treatment within the optimal range. Since the γ' phase is abundant in GH4080A alloy, which leads to a decrease in impact energy, this invention adjusts the aging heat treatment process and reasonably controls the temperature and time of aging treatment to make the amount of γ' precipitation in GH4080A alloy relatively reasonable, so that the impact energy meets the technical requirements. The heat treatment process of this invention is simple, low in cost, and has high commercialization and promotion value. Attached Figure Description

[0024] Figure 1 This is a schematic diagram of an impact energy test according to an embodiment of the present invention. Detailed Implementation

[0025] The technical solution of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0026] This invention provides a heat treatment method for improving the impact energy of GH4080A alloy, comprising the following steps:

[0027] S1: Select the GH4080A alloy to be improved, and put the GH4080A alloy sample into an electric heating furnace for solution treatment: heat up to 1020-1050℃, hold at this temperature for 1-2 hours, and then cool the sample to room temperature with water after taking it out of the furnace.

[0028] S2: The GH4080A alloy treated in step S1 is placed in an electric heating furnace for aging treatment. The aging treatment temperature is 650-750℃ and the time is 9-11h.

[0029] S3: After the aging treatment in step S2 is completed, the GH4080A alloy is taken out of the furnace and cooled to room temperature to complete the heat treatment.

[0030] Preferably, in step S1, the GH4080A alloy comprises the following components:

[0031] C: 0.04%~0.10%; Si: ≤1.0%; Mn: ≤1.0%; S: ≤0.015%; P: ≤0.02%;

[0032] Cr: 18.0%–21.0%; Al: 1.0%–1.8%; Ti: 1.8%–2.7%; B: ≤0.008%; Co: ≤2.0%; Fe: ≤1.5%; Cu: ≤0.2%; balance is nickel and other unavoidable impurities.

[0033] Preferably, the GH4080A alloy comprises the following components:

[0034] C: 0.05%; Si: ≤0.50%; Mn: ≤0.50%; S: ≤0.010%; P: ≤0.010%;

[0035] Cr: 20.0%; Al: 1.2%; Ti: 2.2%; B: ≤0.005%; Co: ≤1.0%; Fe: ≤1.0%; Cu: ≤0.2%; balance is nickel and other unavoidable impurities.

[0036] Preferably, in step S1, the conditions for the solution treatment are: temperature of 1025℃, holding time of 1 hour, and water cooling to room temperature.

[0037] Preferably, in step S2, the aging treatment temperature is 700℃ and the time is 10h.

[0038] Preferably, in step S3, the cooling condition is air cooling.

[0039] The present invention also provides a GH4080A alloy, which is prepared by the above-described heat treatment method.

[0040] Preferably, the impact energy of the GH4080A alloy is greater than 65J.

[0041] The following explanation and description of the above-mentioned technical solution of the present invention, in conjunction with data, are provided:

[0042] Example 1:

[0043] This embodiment provides a heat treatment method for improving the impact energy of GH4080A alloy, including the following steps:

[0044] S1: Select the GH4080A alloy to be improved, and perform solution treatment; hold at 1030℃ for 1 hour, and then water cool to room temperature.

[0045] S2: The GH4080A alloy treated in step S1 is placed in an electric heating furnace for aging treatment. The aging treatment temperature is 700℃ and the time is 10h.

[0046] S3: After the aging treatment in step S2 is completed, the GH4080A alloy is taken out of the furnace and cooled, and then air-cooled to complete the heat treatment.

[0047] The GH4080A alloy comprises the following components:

[0048] C: 0.05%; Si: ≤0.50%; Mn: ≤0.50%; S: ≤0.010%; P: ≤0.010%;

[0049] Cr: 20.0%; Al: 1.2%; Ti: 2.2%; B: ≤0.005%; Co: ≤1.0%; Fe: ≤1.0%; Cu: ≤0.2%; balance is nickel and other unavoidable impurities.

[0050] This embodiment also provides a GH4080A alloy, which is prepared by the above-described heat treatment method.

[0051] Example 2:

[0052] This embodiment provides a heat treatment method for improving the impact energy of GH4080A alloy, including the following steps:

[0053] S1: Select the GH4080A alloy to be improved, and perform solution treatment; hold at 1040℃ for 1 hour, and then water cool to room temperature.

[0054] S2: The GH4080A alloy treated in step S1 is placed in an electric heating furnace for aging treatment. The aging treatment temperature is 650℃ and the time is 11h.

[0055] S3: After the aging treatment in step S2 is completed, the GH4080A alloy is taken out of the furnace and cooled, and then air-cooled to complete the heat treatment.

[0056] Preferably, in step S1, the GH4080A alloy comprises the following components:

[0057] C: 0.04%; Si: ≤1.0%; Mn: ≤1.0%; S: ≤0.015%; P: ≤0.02%; Cr: 18.0%; Al: 1.0%; Ti: 1.8%; B: ≤0.008%; Co: ≤2.0%; Fe: ≤1.5%; Cu: ≤0.2%; balance is nickel and other unavoidable impurities.

[0058] This embodiment also provides a GH4080A alloy, which is prepared by the above-described heat treatment method.

[0059] Example 3:

[0060] This embodiment provides a heat treatment method for improving the impact energy of GH4080A alloy, including the following steps:

[0061] S1: Select the GH4080A alloy to be improved, and perform solution treatment; hold at 1050℃ for 1 hour, and then water cool to room temperature.

[0062] S2: The GH4080A alloy treated in step S1 is placed in an electric heating furnace for aging treatment. The aging treatment temperature is 750℃ and the time is 9h.

[0063] S3: After the aging treatment in step S2 is completed, the GH4080A alloy is taken out of the furnace and cooled, and then air-cooled to complete the heat treatment.

[0064] Preferably, in step S1, the GH4080A alloy comprises the following components:

[0065] C: 0.10%; Si: ≤1.0%; Mn: ≤1.0%; S: ≤0.015%; P: ≤0.02%; Cr: 21.0%; Al: 1.8%; Ti: 2.7%; B: ≤0.008%; Co: ≤2.0%; Fe: ≤1.5%; Cu: ≤0.2%; balance is nickel and other unavoidable impurities.

[0066] This embodiment also provides a GH4080A alloy, which is prepared by the above-described heat treatment method.

[0067] Through analysis, this invention finds that the insufficient impact strength of conventional GH4080A alloy is due to the large number of γ' phases, which leads to a decrease in impact strength. Therefore, this invention controls the precipitation of γ' phase by adjusting the aging heat treatment process, so that the impact strength meets the technical requirements.

[0068] The following comparative examples are provided to illustrate the technical advancements of the present invention as described above:

[0069] Sampling: Four 80mm long samples were taken from the same GH4080A silver bright material after solution treatment, and numbered S1, S2, S3 and S4 respectively. S4 was processed by the heat treatment method of Example 1 above.

[0070] Aging heat treatment: Samples numbered S1, S2, S3, and S4 were placed in a laboratory chamber electric heating furnace. Sample S1 was aged at 700℃ for 16 hours, sample S2 at 700℃ for 14 hours, sample S3 at 700℃ for 12 hours, and sample S4 at 700℃ for 10 hours (i.e., Example 1 of this invention). All samples were air-cooled to room temperature after aging treatment.

[0071] Processing impact test specimens: After aging and cooling, the specimens are machined into 10X10X55mm square strip specimens; then, a 2mm deep V-shaped notch is engraved at 1 / 2 of the longitudinal direction of each square strip specimen, with an included angle of 45° and a root radius of 0.25mm. The symmetry plane of the notch should be perpendicular to the longitudinal axis of the specimen.

[0072] Impact energy test: Place the prepared impact specimen on the anvil of the impact testing machine, and strike the specimen with a pendulum to test the actual impact energy Akv2.

[0073] Results: The impact energy of GH4080A alloy samples treated with different holding times after aging heat treatment is shown in Table 1 below. Figure 1 This is a schematic diagram of an impact energy test according to an embodiment of the present invention.

[0074] Table 1 Impact Energy of GH4080A Alloy Silver Bright Material

[0075] Sample number S1 S2 S3 S4 Aging temperature (°C) 700 700 700 700 Insulation time (h) 16 14 12 10 Cooling method air cooling air cooling air cooling air cooling The standard requires Akv2(J). ≥35 ≥35 ≥35 ≥35 Actual measurement of Akv2(J) 31.2 / 32.6 41.6 / 40.3 58.8 / 59.5 69.2 / 70.5

[0076] Through the above embodiments and comparative examples, it is further demonstrated that by controlling the aging treatment time of GH4080A alloy, the impact energy of the final GH4080A alloy is further improved. The heat treatment method of the present invention effectively improves the comprehensive performance of GH4080A alloy, which has high commercial and promotional value. The present invention improves the impact energy by shortening the holding time of aging heat treatment, while other mechanical properties meet the technical standard requirements, and further reduces the production cost.

[0077] While the disclosure is as stated above, its scope of protection is not limited thereto. Those skilled in the art can make various changes and modifications without departing from the spirit and scope of this disclosure, and all such changes and modifications will fall within the protection scope of this invention.

Claims

1. A method of improving impact energy of a GH4080A alloy by heat treatment, characterized in that: Includes the following steps: S1: Select the GH4080A alloy to be improved, and place the GH4080A alloy sample into an electric heating furnace for solution treatment: heat to 1025℃, hold at this temperature for 1 hour, and then remove from the furnace and cool the sample to room temperature with water; S2: Place the GH4080A alloy treated in step S1 into an electric heating furnace for aging treatment. The holding temperature for the aging treatment is 700℃, and the holding time is 10 hours; S3: Remove the GH4080A alloy sample after the aging treatment in step S2 from the furnace, and allow the sample to cool to room temperature to complete the heat treatment. In step S1, the GH4080A alloy comprises the following components: C: 0.04% to 0.10%; Si: ≤1.0%; Mn: ≤1.0%; S: ≤0.015%; P: ≤0.02%; Cr: 18.0%~21.0%; Al：1.0％～1.8％； Ti: 1.8%–2.7%; B: ≤0.008%; Co: ≤2.0%; Fe: ≤1.5%; Cu: ≤0.2%; balance is nickel and other unavoidable impurities; In step S3, the cooling condition is air cooling.

2. The heat treatment method for improving the impact energy of GH4080A alloy according to claim 1, characterized in that: The GH4080A alloy comprises the following components: C: 0.05%; Si: ≤0.50%; Mn: ≤0.50%; S：≤0.010％； P: ≤0.010%; Cr: 20.0%; Al: 1.2%; Ti: 2.2%; B: ≤0.005%; Co: ≤1.0%; Fe: ≤1.0%; Cu: ≤0.2%; balance is nickel and other unavoidable impurities.

3. A GH4080A alloy, characterized in that: The GH4080A alloy is prepared by any one of the heat treatment methods according to claims 1-2.

4. The GH4080A alloy according to claim 3, characterized in that: The impact energy of the GH4080A alloy is greater than 35J.

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