The heat treatment strengthening method of the Inconel718 and Rene' 41 dissimilar high-temperature alloy welded structural part is characterized by comprising the following steps of:

(1) carrying out solution heat treatment on the Inconel718 high-temperature alloy;

(2) carrying out solution heat treatment and aging heat treatment on the Rene' 41 high-temperature alloy;

(3) and welding the solid solution Inconel718 and the aged Rene' 41, and performing aging heat treatment on the welded structural part.

2. The method for heat-treating and strengthening the Inconel718 and Rene' 41 dissimilar superalloy welded structure according to claim 1, wherein: and (3) performing solution heat treatment in the step (1) at the temperature of 941-1010 ℃, preserving heat for 1h, and cooling in air to room temperature.

3. The method for heat treatment strengthening of the Inconel718 and Rene' 41 dissimilar superalloy welded structure according to claim 1 or 2, wherein: and 2, performing solid solution heat treatment at 1079 ℃, preserving the heat for 1 hour, and cooling the air to room temperature.

4. The heat treatment strengthening method for the Inconel718 and Rene' 41 dissimilar high-temperature alloy welded structural member according to any one of claims 1 to 3, wherein the heat treatment strengthening method comprises the following steps: and 2, performing aging heat treatment at 760 ℃, preserving the heat for 15-17 h, and air-cooling to room temperature.

5. The heat treatment strengthening method for the Inconel718 and Rene' 41 dissimilar high-temperature alloy welded structural member according to any one of claims 1 to 4, wherein the heat treatment strengthening method comprises the following steps: and step 3, the aging heat treatment system is 718-760 ℃, the temperature is kept for 8h, the furnace is cooled to 621-649 ℃ at the speed of 48-64 ℃/h, the temperature is kept for 8h, and the air cooling is carried out.

6. The heat treatment strengthening method for the Inconel718 and Rene' 41 dissimilar high-temperature alloy welded structural member according to any one of claims 1 to 5, wherein the heat treatment strengthening method comprises the following steps: the welding adopts argon arc welding.

7. The heat treatment strengthening method for the Inconel718 and Rene' 41 dissimilar high-temperature alloy welded structural member according to any one of claims 1 to 6, wherein the heat treatment strengthening method comprises the following steps: the Inconel718 alloy may alternatively employ GH4169 or UNS N07718.

8. The heat treatment strengthening method for the Inconel718 and Rene' 41 dissimilar high-temperature alloy welded structural member according to any one of claims 1 to 7, characterized by comprising the following steps of: the Rene' 41 alloy can alternatively adopt GH141 or UNS N07041.

Background

The nickel-based high-temperature alloy has excellent performance at medium and high temperature, the Inconel718 has good fatigue resistance, radiation resistance, oxidation resistance and corrosion resistance, good processing performance, welding performance and long-term structure stability, and becomes the most widely applied nickel-based high-temperature alloy in the history of aeroengines, the Rene' 41 has high tensile and lasting creep strength and good oxidation resistance at 650-900 ℃, and the material has good plasticity after deformation. Inconel718 and Rene '41 are common materials for parts such as aeroengine turbines, casings, blades and the like, the similar designations of the Inconel718 are GH4169 and UNS N07718, the similar designations of the Rene' 41 are GH141 and UNS N07041, and both high-temperature alloys are solid solution aging strengthening nickel-based high-temperature alloys. The solid solution strengthening and age hardening high temperature alloy weldment is generally welded in a solid solution or annealing state, has better weldability, plasticity and compactness, and high joint strength, and the age hardening alloy has the risks of welding crack and low performance if the age hardening alloy is welded in an aging state.

Related researches on the deformation strengthening heat treatment of Inconel718 and Rene' 41 nickel-based high-temperature alloys are carried out at home and abroad, but the researches are based on single material performance researches. In addition, due to structural design reasons, different high-temperature alloy parts are required to be welded to be used as structural parts, while Incone718 and Rene '41 are used as common materials for nickel-based high-temperature alloys, so that research on welding technology and process of Inconel718 and Rene' 41 different high-temperature alloys has been carried out at present, but most of the content is based on research on welding parameters and weld performance of two high-temperature alloys, and no relevant report is provided on how to achieve the aging state performance of each base metal by adopting an aging heat treatment method after welding of base metals in a solid solution state or an annealing state of the different high-temperature alloys.

Disclosure of Invention

The invention solves the technical problem that no effective heat treatment method exists at present for enabling a welding line and a base metal to simultaneously meet the requirement of service performance aiming at the dissimilar nickel-based high-temperature alloy.

Aiming at the problems, the invention provides a heat treatment strengthening method of an Inconel718 and Rene' 41 dissimilar high-temperature alloy welded structural part, which comprises the following steps:

(1) carrying out solution heat treatment on the Inconel718 high-temperature alloy;

(2) carrying out solution heat treatment and aging heat treatment on the Rene' 41 high-temperature alloy;

(3) and welding the solid solution state Inconel718 and the aged state Rene' 41 by argon arc welding, and then carrying out aging heat treatment on the welded structural part. The welding structure comprises a base material and a welding joint.

Further, the temperature of the solution heat treatment in the step 1 is 941-1010 ℃ for 1h, and the air cooling is carried out to the room temperature.

Further, the temperature of the solution heat treatment in the step 2 is 1079 ℃, the temperature is 1h, and the air cooling is carried out to the room temperature.

Further, the temperature of the aging heat treatment in the step 2 is 760 ℃, 15-17 h, and the air cooling is carried out to the room temperature.

Further, the aging heat treatment system in the step 3 is 718-760 ℃, the temperature is kept for 8h, the furnace is cooled to 621-649 ℃ at 48-64 ℃/h, the temperature is kept for 8h, and the furnace is cooled to the room temperature.

Wherein, the welding adopts argon arc welding.

Among them, the Inconel718 alloy can be replaced by GH4169 or UNS N07718.

Wherein GH141 or UNS N07041 can be used alternatively for Rene' 41 alloy.

The beneficial effects produced by the invention are as follows:

compared with the existing single alloy heat treatment strengthening method and the existing dissimilar superalloy welding process, the heat treatment method enables the properties of the Inconel718 and Rene' 41 welded structural parts to finally meet the mechanical property requirements of the base metal and welding seam standards;

the method is simple to operate, convenient to execute and wide in application prospect, and can provide a technical method for application of dissimilar high-temperature alloy welding components in design and manufacture of aero-engines.

Detailed Description

In the actual production process, the high-temperature alloy is adopted to manufacture parts in the design structure, the high-temperature alloy has better mechanical property and high-temperature resistance after solid solution aging strengthening is mainly considered, and the performance of the material after the aging strengthening is achieved meets the use requirement of the parts. The heat treatment method provided by the invention is characterized in that before and after the Inconel718 and Rene' 41 dissimilar high-temperature alloys are welded, the corresponding heat treatment method is adopted to enable each base metal to meet the requirement of respective aging strengthening performance, and meanwhile, the welding line also meets the corresponding mechanical property requirement, so that the heat treatment method has practical significance for the use of the aircraft engine dissimilar high-temperature alloy welded structural member.

The welding process is not particularly limited, and argon arc welding is preferably adopted.

As a preferred embodiment, the welding misalignment is not more than 0.3mm, the assembly gap is not more than 0.5mm, the width and the rest height of the welding seam are not more than 75% of the size of the welding seam, and cracks, slag inclusions, craters, burning-through and the like are not required to exist on the welding seam.

As a preferred embodiment, before welding, the surface to be welded is cleaned (polished or acid-washed or wiped by alcohol acetone), assembly positioning welding is carried out by adopting a manual argon arc welding machine, welding is carried out by adopting an automatic argon arc welding machine, after welding, the quality of the welding line is detected by adopting a fluorescence and x-ray method, and heat treatment is carried out after the welding line is qualified.

In a preferred embodiment, the invention is cooled to room temperature after welding and then subjected to an aging treatment.

Since the dissimilar alloys of the present invention are not limited to only Inconel718 and Rene' 41, the specific heat treatment schedule in the solution or aging treatment can be routinely adjusted for different alloys.

Example 1

Carrying out solution heat treatment on the Inconel718 high-temperature alloy, carrying out heat preservation for 1 hour after thorough heat exchange at 980 ℃, and carrying out air cooling to room temperature; carrying out solid solution and aging heat treatment on the Rene' 41 high-temperature alloy, carrying out heat preservation for 1h after heat penetration at 1079 ℃, carrying out air cooling to room temperature, carrying out heat preservation for 16 h after heat penetration at 760 ℃, and carrying out air cooling to room temperature; and welding the solid solution state Inconel718 and the aging state Rene' 41 by adopting an argon arc welding butt joint, then carrying out aging treatment, completely heating at 760 ℃, keeping the temperature for 8 hours, cooling the furnace to 633 ℃, keeping the temperature for 8 hours, and cooling the furnace to room temperature.

Example 2

Carrying out solution heat treatment on the Inconel718 high-temperature alloy, carrying out heat penetration at 960 ℃, then carrying out heat preservation for 1 hour, and carrying out air cooling to room temperature; carrying out solid solution and aging heat treatment on the Rene' 41 high-temperature alloy, carrying out heat preservation for 1h after heat penetration at 1079 ℃, carrying out air cooling to room temperature, carrying out heat preservation for 16 h after heat penetration at 760 ℃, and carrying out air cooling to room temperature; and welding the solid solution state Inconel718 and the aging state Rene '41 by adopting an argon arc welding butt joint, then carrying out aging treatment, carrying out heat preservation for 8 hours after the solid solution state Inconel718 and the aging state Rene' 41 are thoroughly heated at 730 ℃, carrying out furnace cooling to 633 ℃, carrying out heat preservation for 8 hours, and carrying out air cooling to room temperature.

Example 3

Carrying out solution heat treatment on the Inconel718 high-temperature alloy, carrying out heat thorough heating at 945 ℃, then carrying out heat preservation for 1 hour, and carrying out air cooling to room temperature; carrying out solid solution and aging heat treatment on the Rene' 41 high-temperature alloy, carrying out heat preservation for 1h after heat penetration at 1079 ℃, carrying out air cooling to room temperature, carrying out heat preservation for 16 h after heat penetration at 760 ℃, and carrying out air cooling to room temperature; and welding the solid solution state Inconel718 and the aging state Rene' 41 by adopting an argon arc welding butt joint, then carrying out aging treatment, completely heating at 720 ℃, keeping the temperature for 8 hours, cooling the furnace to 633 ℃, keeping the temperature for 8 hours, and cooling the furnace to room temperature.

Comparative example 1

Carrying out solid solution and aging heat treatment on the Inconel718 high-temperature alloy, carrying out heat preservation for 1 hour after the heat is thoroughly conducted at 980 ℃, carrying out air cooling to room temperature, carrying out heat preservation for 8 hours after the heat is thoroughly conducted at 730 ℃, carrying out furnace cooling to 633 ℃, carrying out heat preservation for 8 hours, and carrying out air cooling to room temperature; carrying out solid solution and aging heat treatment on the Rene' 41 high-temperature alloy, carrying out heat preservation for 1h after heat penetration at 1079 ℃, carrying out air cooling to room temperature, carrying out heat preservation for 16 h after heat penetration at 760 ℃, and carrying out air cooling to room temperature; and performing argon arc welding butt joint welding on the aged Inconel718 and the aged Rene' 41.

Comparative example 2

Carrying out solution heat treatment on the Inconel718 high-temperature alloy, carrying out heat preservation for 1 hour after thorough heat exchange at 980 ℃, and carrying out air cooling to room temperature; carrying out solution heat treatment on the Rene' 41 high-temperature alloy, carrying out heat preservation for 1h after thorough heat at 1079 ℃, and carrying out air cooling to room temperature; and (3) welding a butt joint of the solid solution Inconel718 and the solid solution Rene' 41 by adopting argon arc welding, then performing aging treatment on the base material and the joint, carrying out heat preservation for 16 hours after the base material and the joint are thoroughly heated at 760 ℃, and carrying out air cooling to room temperature.

Examples of Performance test

The room temperature tensile test method adopts ASTM E8/E8M, the hardness test method adopts ASTM E10, the high temperature tensile test method adopts ASTM E21, and the high temperature endurance test method adopts ASTM E292.

Table 1 shows properties of Inconel718 base materials obtained by different heat treatment methods, and it can be seen from table 1 that the properties of the Inconel718 base materials obtained in examples 1 to 3 after solid solution treatment before welding and after aging treatment after welding meet the acceptance requirements, and the Inconel718 base materials obtained in comparative example 2 do not meet the acceptance requirements in terms of room-temperature tensile yield strength.

Table 2 shows the properties of Rene '41 parent metal obtained by different heat treatment methods, and it can be seen from Table 2 that the performance of Rene' 41 in examples 1-3 after double aging meets the acceptance requirements.

When different materials are combined and welded, the tensile strength of the butt joint is calculated according to the base material with lower strength, and the tensile strength of the welded II-type butt joint is not lower than 90% of the lower limit of the strength limit specified by the technical conditions of the base material, namely the tensile strength of the Inconel718 and Rene' 41 dissimilar high-temperature alloy after welding is required to be not less than 1054.8MPa (1172MPa multiplied by 90%). Table 3 shows that the tensile strength of the joints obtained by different heat treatment methods in examples 1-3 meets the standard requirements, and after the welding of examples 1-3, the metallographic structure of the weld fusion zone does not contain dense oxides and inclusions, the X-ray detection and the fluorescence detection of the II-grade weld are qualified, and the tensile strength of the welded joints after the aging of the two high-temperature alloys in comparative example 1 does not meet the acceptance requirements.

TABLE 1 Inconel718 parent Material Properties

TABLE 2 Rene' 41 parent Metal Properties

TABLE 3 tensile Strength of the joints

The foregoing is a more detailed description of the invention in connection with specific/preferred embodiments and is not intended to limit the practice of the invention to those descriptions. Several alternatives or modifications to the described embodiments may be made without departing from the inventive concept and such alternatives or modifications should be considered as falling within the scope of the present invention.