阅读说明：本技术 一种航空用PH13-8Mo零件的加工方法 (Method for processing aviation PH13-8Mo part ) 是由 王少阳 沈明 张立新 王力强 陈丽丽 于 2019-10-23 设计创作，主要内容包括：本发明公开了一种航空用PH13-8Mo零件的加工方法,包括以下步骤：1)PH13-8Mo棒材经下料、制坯,并经过至少一次模锻、切边后形成一定形状的锻件,并在600~760℃退火,消除锻造过程中的残余应力；2)对锻件进行固溶处理；3)接着对锻件进行冷处理；4)冷处理完成后,对锻件进行粗加工,初步形成毛坯零件；5)对制成的毛坯零件进行人工时效处理；6)最后对毛坯零件进行精加工,制成成品。本发明采用“冷热结合”工艺方案,零件在固溶状态下粗加工,在较低的硬度下完成大部分材料的去除工作,提高切削速度,降低刀具损耗量；在粗加工后锻件等效厚度降低,减少后续人工时效时的加热时间和能耗,还能对零件变形进行热校正,消除部分加工应力,降低零件的变形量。(The invention discloses a method for processing an aviation PH13-8Mo part, which comprises the following steps of 1) blanking and blank-making a PH13-8Mo bar, forming a forging piece with a certain shape after at least one time of die forging and edge cutting, and annealing at 600 ~ 760 ℃ to eliminate residual stress in the forging process, 2) carrying out solution treatment on the forging piece, 3) carrying out cold treatment on the forging piece, 4) carrying out rough machining on the forging piece after the cold treatment is finished to preliminarily form a blank part, 5) carrying out artificial aging treatment on the manufactured blank part, and 6) finally carrying out finish machining on the blank part to obtain a finished product.)

1. A method for processing an aviation PH13-8Mo part is characterized by comprising the following steps:

(1) blanking and blanking a PH13-8Mo bar, performing at least one-time die forging and trimming to form a forging piece with a certain shape, and annealing at 600 ~ 760 ℃ to eliminate residual stress in the forging process;

(2) carrying out solution treatment on the forging;

(3) then, carrying out cold treatment on the forging;

(4) after the cold treatment is finished, roughly machining the forge piece to preliminarily form a blank part;

(5) carrying out artificial aging treatment on the prepared blank part;

(6) and finally, performing finish machining on the blank part to obtain a finished product of the aviation PH13-8Mo part.

2. The method for processing the PH13-8Mo part for aviation according to claim 1, wherein in the step (1), the die forging is performed once or twice, and in the secondary die forging, the secondary die forging is performed after the forged piece of the primary die forging is subjected to trimming or cleaning.

3. The method for processing the PH13-8Mo part for aviation use as claimed in claim 2, wherein in the step (2), the forging is subjected to solution treatment by heating the forging to 800 ~ 1000 ℃ and keeping the temperature for 150 ~ 1800 minutes, then heating the forging to 5 ~ 45 ℃ and keeping the temperature for 50 ~ 90 minutes, and cooling to room temperature.

4. The method for processing the PH13-8Mo part for aviation use as claimed in claim 3, wherein in the step (2), the forging is heated to 900 +/-10 ℃ and is kept warm for 180 +/-15 minutes, then the temperature is raised to 925 +/-10 ℃ and is kept warm for 60 +/-6 minutes, and cooling oil is used for cooling to room temperature, and the cooling time is not less than 45 minutes.

5. The method for processing the aeronautical PH13-8Mo part as claimed in claim 1 ~ 4, wherein in the step (3), the forging is subjected to the cold treatment process, namely, the forging is cooled to-50 ~ 20 ℃ and is kept warm for 60 ~ 1200 minutes and 1200 minutes, and then the forging is placed in an external environment to be cooled to room temperature.

6. The method for processing the PH13-8Mo part for aviation use as claimed in claim 5, wherein in step (3), the forging is cooled to 0 ± 5 ℃ by manual temperature control and kept at the temperature for 0 ± 5 ℃ for minutes, and then placed in an external environment, and the temperature is kept to room temperature, so as to realize solid solution stabilization of the PH13-8Mo material and avoid precipitation of precipitated phase.

7. The method for machining the PH13-8Mo part for aviation as claimed in any one of claims 1 ~ 4, wherein in the step (4), the rough machining of the forging requires that the outer layer of the forging is milled away by a milling cutter for at least 5mm, a machining allowance of at least 5mm is reserved according to the shape of the part, and after the part is subjected to ultrasonic flaw detection, the machining allowance of 4mm is reserved for the shape of the part.

8. The method for manufacturing an aviation PH13-8Mo part as claimed in claim 1 ~ 4, wherein in the step (5), the blank part is artificially aged by heating the blank part to 500 ~ 540 ℃ and keeping the temperature for 30 ~ 2400 and 2400 minutes, then heating to 540 +/-5 ℃, keeping the temperature for 120 ~ 300 minutes, placing the blank part in a room temperature environment, and naturally cooling the blank part by using air.

9. The method for processing the PH13-8Mo part for aviation according to claim 8, wherein in the step (5), the blank part is precipitation hardened by manual heating, the blank part is heated to 500 +/-5 ℃ and is kept warm for 60 +/-6 minutes, then is heated to 540 +/-5 ℃ and is kept warm for 240 +/-15 minutes, and is placed in a room temperature environment and is naturally cooled by air.

10. The method for machining an aviation PH13-8Mo part as claimed in claim 1 ~ 4, wherein in the step (6), the blank part is finished by half-finish-milling the inner and outer shapes, natural aging, flattening the datum plane according to the deformation, finish-milling the datum plane and the datum hole, and finish-milling the inner and outer shapes to obtain the finished part.

Technical Field

The invention relates to the technical field of metal material processing, in particular to a method for processing an aviation PH13-8Mo part.

Background

The PH13-8Mo (0 Cr13Ni8Mo2 Al) stainless steel has high strength, good fracture toughness and good transverse mechanical property, and can have excellent stress corrosion resistance in ocean and oil gas environments. Because of the good comprehensive performance of the grade steel, the grade steel is widely applied to the parts of frames and beams of critical stress of airplanes, oil tanks in severe working environments and the like.

In order to obtain the best metal streamline distribution and eliminate the casting defects in raw materials, a PH13-8Mo forging is used as a raw material for machining an aviation PH13-8Mo part, in order to enable the PH13-8Mo to reach the mechanical property required by the standard, the PH13-8Mo forging needs to be subjected to a series of heat treatments, and the working procedures are solid solution treatment, cold treatment and artificial aging, wherein in the solid solution working procedure, the material is rapidly cooled to room temperature at 925 ℃, the cold treatment is to place the forging in an environment at 0 ℃ for heat preservation for a plurality of hours and then take out, and finally, the aging is carried out at 500 ~ 540 ℃ to enable the material to be subjected to precipitation hardening, so that the comprehensive mechanical property with high strength and high fracture toughness can be obtained.

The size and precision requirements of the aviation parts are continuously improved along with the integration and large-scale design of airplane parts, the length of the parts can reach more than two meters, the parts mainly comprise thin walls and ribs with the thickness of 1 ~ mm, and meanwhile, the warping of the parts is controlled within 0.1 mm.

Disclosure of Invention

The invention aims to provide a method for machining an aviation PH13-8Mo part, which can reduce the comprehensive machining cost of the aviation PH13-8Mo part, improve the machining efficiency, ensure sufficient performance of materials and ensure the machining precision of the aviation PH13-8Mo part.

The invention is realized by the following technical scheme: a method for processing an aviation PH13-8Mo part comprises the following steps:

(1) blanking and blanking a PH13-8Mo bar, performing at least one-time die forging and trimming to form a forging piece with a certain shape, and annealing at 600 ~ 760 ℃ to eliminate residual stress in the forging process;

(2) carrying out solution treatment on the forging;

(3) then, carrying out cold treatment on the forging;

(4) after the cold treatment is finished, roughly machining the forge piece to preliminarily form a blank part;

(5) carrying out artificial aging treatment on the prepared blank part;

(6) and finally, performing finish machining on the blank part to obtain a finished product of the aviation PH13-8Mo part.

According to the technical scheme, the artificial aging process is arranged after the forging rough machining process, the traditional process method with completely independent heat treatment and cold machining processes is changed, rough machining is carried out in a heat treatment state with lower PH13-8Mo material hardness, and most materials are removed; then, before finish machining, carrying out artificial aging treatment under the condition of ensuring enough machining allowance, thereby obtaining the comprehensive mechanical property of the material; and finally, correcting the deformation of the part through finish machining to ensure the geometric dimension precision of the part.

In order to better implement the invention, further, in the step (1), the number of times of die forging is determined according to the complexity of the part to be processed, generally, the number of times of die forging is one or two, and in the case of secondary die forging, the secondary die forging can be performed after the forged piece of the primary die forging is trimmed or cleaned.

In order to better implement the method, in the step (2), the solution treatment process of the forging is to heat the forging to 800 ~ 1000 ℃ and preserve heat for 150 ~ 1800 minutes, heat the forging to 5 ~ 45 ℃ and preserve heat for 50 ~ 90 minutes, and cool the forging to room temperature.

In order to better realize the invention, in the step (2), the forging is heated to 900 +/-10 ℃, the temperature is kept for 180 +/-15 minutes, then the temperature is raised to 925 +/-10 ℃, the temperature is kept for 60 +/-6 minutes, cooling oil is used for cooling the forging to the room temperature, and the cooling time is not less than 45 minutes.

In order to better implement the invention, in the step (3), the forging is subjected to cold treatment by cooling the forging to-50 ~ 20 ℃, keeping the temperature for 60 ~ 1200 minutes, and then placing the forging in an external environment until the temperature reaches room temperature.

In order to better realize the method, in the step (3), the temperature of the forging is manually controlled to be cooled, the temperature of the forging is reduced to 0 +/-5 ℃, the temperature is kept for 0 +/-5 ℃ for minutes, then the forging is placed in an external environment, and when the temperature of the forging is reduced to room temperature, the solid solution stabilization of the PH13-8Mo material is realized, and the precipitation of a precipitation phase is avoided.

In order to better implement the method, further, in the step (4), the rough machining of the forged piece needs to mill off at least 5mm of the outer layer of the forged piece by using a milling cutter, and to reserve a machining allowance of at least 5mm according to the appearance of the part, and after ultrasonic flaw detection is performed on the part, the shape of the part is guaranteed to reserve a machining allowance of 4 mm.

In order to better implement the invention, in the step (5), the artificial aging treatment process of the blank part comprises the steps of heating the blank part to 500 ~ 540 ℃, preserving heat for 30 ~ 2400 minutes, then heating to 540 +/-5 ℃, preserving heat for 120 ~ 300 minutes, placing the blank part in a room temperature environment, and naturally cooling by using air.

In order to better implement the method, in the step (5), the blank part is subjected to precipitation hardening in a manual heating mode, the blank part is heated to 500 +/-5 ℃, is subjected to heat preservation for 60 +/-6 minutes, is heated to 540 +/-5 ℃, is subjected to heat preservation for 240 +/-15 minutes, is placed in a room temperature environment, and is naturally cooled by air.

In order to better realize the invention, in the step (6), the blank part is subjected to finish machining, wherein the inner shape and the outer shape are firstly subjected to semi-finish milling, natural aging is carried out, then the reference surface is leveled according to the deformation, the reference surface and the reference hole are subjected to finish milling, and the inner shape and the outer shape are subjected to finish milling to obtain a finished part.

Compared with the prior art, the invention has the following advantages and beneficial effects:

(1) according to the invention, the artificial aging process is set in the mechanical processing (in the process, the artificial aging (precipitation hardening) is carried out after the rough machining of the forge piece is finished), so that the mechanical processing efficiency is improved, and the cutter abrasion is reduced;

(2) according to the invention, a 'cold and hot combination' process scheme is adopted, the part is roughly processed in a solid solution state, most of materials are removed under lower hardness, at the moment, the material hardness is 38HRC (the material hardness after aging is more than 45 HRC), the cutting speed can be improved by 15%, and the tool loss can be reduced by 10 ~ 20%;

(3) the forging equivalent thickness after rough machining is reduced, the heating time and the energy consumption during subsequent artificial aging can be effectively reduced, the deformation released in the rough machining process can be subjected to thermal correction, and a part of machining stress is eliminated, so that the deformation amount during part fine machining is further reduced, and the forging equivalent thickness reduction method is suitable for being widely applied to the manufacturing process of aviation parts.

Drawings

Other features, objects and advantages of the invention will become more apparent upon reading of the detailed description of non-limiting embodiments with reference to the following drawings:

FIG. 1 is a schematic view of a specific process flow of the processing method of the present invention.

Detailed Description

The present invention will be described in further detail with reference to examples, but the embodiments of the present invention are not limited thereto, and various substitutions and alterations can be made without departing from the technical idea of the present invention as described above, according to the common technical knowledge and the conventional means in the field.

The present invention will be described in further detail with reference to the following examples for the purpose of making clear the objects, process conditions and advantages of the present invention, which are given by way of illustration only and are not intended to be limiting of the present invention.