Forming method of Y-type AerMet100 structural steel die forging

Abstract

The invention relates to the field of forging and die design, in particular to a forming method of a Y-type AerMet100 structural steel die forging. The method comprises the steps that a raw material bar is subjected to blank making, and a Y-shaped rough shape is obtained; and the Y-shaped rough shape is subjected to die forging, and the Y-type AerMet100 structural steel die forging is obtained. The forging forming method ensures the structure property of the forge piece, improves the utilization rate of raw materials and reduces the production cost of the forge piece.

Description

Technical Field

[0001] The invention relates to the field of forging and die design, and in particular to a forming method for a "Y" type AerMet100 structural steel die forging. Background Art

[0002] A-100 steel is currently the best high-alloy ultra-high strength steel with the best combination of strength and toughness, and is the preferred material for aircraft landing gear. For large aircraft landing gear, the process design window is narrow and difficult, and the reasonable matching between the forging structure and forming design, as well as the forging microstructure and performance, has become one of the difficulties in delivering qualified forgings.

[0003] A-100 forging material for a certain aircraft landing gear, the forging projection area is about 0.2m 2 The forging belongs to the fork-shaped forging. The forging consists of two parts. The front end is the fork-shaped area (similar to the shape of a "U"), and the rear end is the rod area. The forging has a boss and a large change in cross-sectional size. The ratio of the maximum cross-sectional area to the minimum cross-sectional area is 5.3, and the maximum cross-sectional area is 0.048m 2 , the minimum cross-sectional area is 0.009m 2 A large amount of data shows that the deformation of A-100 steel forgings needs to be greater than 30% to obtain forgings with uniform structure and qualified performance. Summary of the invention

[0004] Purpose of the invention: hot material is returned to the furnace for the first time in die forging, the first fire is 960℃, matching small deformation (≥10%); the hot material is directly returned to the furnace after the first fire die forging, and the temperature is continued to rise rapidly, reducing the time of forgings in the high temperature section, ensuring the organization (grain size) and performance of the forgings. Second, the "Y" type AerMet100 structural steel die forgings are obtained by upsetting and widening the bar material into a "T" type intermediate billet, and then using special tooling to make the "T" type intermediate billet into a "Y" type rough shape, and then the "Y" type rough shape is obtained by die forging.

[0005] Technical solution:

[0006] A method for forming a "Y" type AerMet100 structural steel die forging is provided, comprising:

[0007] The raw material bar is blanked to obtain a "Y" shaped rough shape;

[0008] The “Y”-shaped rough shape is die-forged to obtain the “Y” type AerMet100 structural steel die forgings;

[0009] Furthermore, the raw material bar is blanked to obtain a "Y"-shaped rough shape, including:

[0010] Upsetting, widening and thinning the raw material bars into rectangular plates;

[0011] Put the rectangular plate into the lower mold, and use the upper flat anvil to make the blank to obtain a "T" shaped rough shape;

[0012] The "T"-shaped rough shape is placed in the lower tire mold, and the upper tire mold is used to make a blank to obtain a "Y"-shaped rough shape;

[0013] The "Y" type structural steel die forgings are obtained by die forging the "Y" shaped rough shape.

[0014] Furthermore, different parting methods are used for "Y"-shaped and "Y"-type structural steel die forgings:

[0015] The "Y"-shaped rough shape adopts plane parting, and the "Y"-type structural steel die forgings adopts broken line parting.

[0016] Furthermore, the number of fires required for the "Y"-shaped rough die forging is N, where N is less than or equal to 2.

[0017] Furthermore, when N=1, the "Y" type rough type is heated to a preheating temperature of 850°C, kept warm for a certain period of time, and then quickly heated to 1030°C~1040°C. The uniformity of the high temperature stage of the heating furnace is controlled within the range of -5°C~+5°C.

[0018] Furthermore, when N=2, the first fire: the "Y" type rough type is first heated to the preheating temperature of 850℃, kept warm for a certain period of time, and then quickly heated to 960℃~1000℃. The uniformity of the high temperature stage of the heating furnace is controlled within -10℃~+10℃;

[0019] Second fire: After the first forging fire, the hot material is directly returned to the furnace without cooling, and the temperature is quickly raised to 1000℃~1040℃. It is kept warm for a certain period of time. The uniformity of the high temperature stage of the heating furnace is controlled within -5℃~+5℃.

[0020] Furthermore, the second fire: after the first die forging fire, the hot material is directly returned to the furnace without cooling, and the temperature is directly and quickly raised to 1000℃~1040℃, and the temperature is kept for a certain period of time. The uniformity of the high temperature stage of the heating furnace is controlled within -5℃~+5℃, including:

[0021] The hot material is returned to the furnace for the first time, and the first fire is heated to 960℃~1000℃ to match the small deformation; after the first fire, the forging is directly returned to the furnace with hot material, and the temperature continues to be rapidly increased to 1000℃~1040℃, and kept warm for a certain period of time, and the "Y" type AerMet100 structural steel die forgings are obtained by forging.

[0022] Furthermore, the above-mentioned certain insulation time is half of the insulation time of the first fire.

[0023] Beneficial effects:

[0024] The present invention is to obtain a "T"-shaped intermediate blank by upsetting and widening a bar material, and then bend it into a "Y"-shaped rough shape by a tooling, and obtain a die forging of "Y" type AerMet100 structural steel by die forging. Compared with conventional forging, it is necessary to add a skin on the basis of the die forging, and it is also necessary to meet the requirements of the forging by removing the skin before delivery. The design concept of the present invention is: first, breaking the traditional design concept, not following the conventional design, and adding a skin in the fork-shaped area for forging; second, after the first fire of die forging, the hot material is returned to the furnace, and the forging is continued to be heated up before forging, so as to reduce the heat preservation time of the forging in the high temperature area and ensure the microstructure and performance of the forging; third, at the same time, special tooling is used to make the blank, combined with the material characteristics of AerMet100, the deformation of the forging is increased, and the microstructure and performance of the forging are ensured; fourth, the skin-free design reduces the weight of the forging, and at the same time increases the utilization rate of the raw materials, omits the removal process of removing the skin of the forging, reduces the production cost, and improves the production efficiency of the forging. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1-1 It is a schematic axial side view of a die forging of "Y" type AerMet100 structural steel of the present invention;

[0026] Figure 1-2 The parting surface of the die forging of the "Y" type AerMet100 structural steel of the present invention is a broken line;

[0027] Figure 2 It is a schematic diagram of the "T"-shaped rough shape in the tooling 1 of the present invention;

[0028] Figure 3 It is a structural schematic diagram of a "T"-shaped rough shape and a "Y"-shaped rough shape of the present invention;

[0029] Among them, 1 is the upper anvil of tooling 1, 2 is the lower tire mold of tooling 1, 3 is a "T"-shaped intermediate blank, 5 is the upper tire mold of tooling 2. 5 is the lower tire mold of tooling 2, and 6 is a "Y"-shaped blank. DETAILED DESCRIPTION

[0030] For this type of forging, conventionally, the forked area of ​​the forging is designed with a continuous skin, and the forging is directly made and die-forged using the bar material to meet the requirements of forging forming. The present invention adopts special tooling for making and die-forging to obtain a "Y" type structural steel die forging, and after adjusting the forging parameters, a forging with uniform structure and qualified performance is obtained. The design of the present invention improves the material utilization rate of the forging and saves production costs.

[0031] The present invention provides a method for forming a "Y" type AerMet100 structural steel die forging, comprising:

[0032] After the bar is upset along the streamline direction to form a "square plate", the "tool 1" is used to split the plate and partially thin it to obtain a "T"-shaped intermediate blank, and then a similar "Y"-shaped tool 2 is used to bend it and then straighten it to obtain a "Y"-shaped rough shape;

[0033] The “Y”-shaped rough shape is forged to obtain a “Y” type AerMet100 structural steel die forging;

[0034] Furthermore, the raw material bar needs to be fired twice to form a rough shape. In the first fire, the bar is preheated to 850°C, heated for a period of time, and quickly heated to 1130°C. In the second fire, the "T"-shaped intermediate billet is made into a "Y"-shaped rough shape using a special tool. The "T"-shaped intermediate billet is heated to the preheating temperature of 850°C, kept warm for a period of time, and quickly heated to 960°C, heated for a period of time (half of the heating period), and the holding time of the hot material returned to the furnace is halved. The temperature uniformity of the heating furnace is controlled at ±10°C; the "Y"-shaped rough shape is obtained. In order to position the subsequent die forging, the forging is positioned by one end of the fork area and the rear end head of the rod.

[0035] Furthermore, the Y-shaped rough shape design adopts a different parting method from the Y-shaped AerMet100 structural steel die forging. The Y-shaped rough shape design adopts a plane parting method, while the Y-shaped AerMet100 structural steel die forging adopts a broken line parting method. For the positioning of the subsequent die forging, the Y-shaped rough shape is positioned by one end of the fork area and the rear end of the rod to ensure that the rough shape will not move in the length direction during the bending process.

[0036] Furthermore, the "Y" type rough die forging is formed into a "Y" type AerMet100 structural steel die forging. The "Y" type AerMet100 structural steel die forging requires two fires, the first fire: the "Y" type rough die preheating temperature is 850℃, kept warm for a period of time, and quickly heated to 960℃, kept warm for a certain period of time, and the furnace temperature uniformity of the heating furnace is controlled at ±5℃; the second fire: quickly heated to 1030, the uniformity of the high temperature stage of the heating furnace is controlled at ±5℃, the second fire of the forging is hot material return to the furnace, and the time of hot material return to the furnace is halved. According to the characteristics of A-100 material, the deformation of the forging is required to meet ≥30% to ensure the structure and performance of the forging. The present invention uses hot material return to the furnace for the first time, the first fire is 960℃, matching small deformation (≥10%); the hot material is directly returned to the furnace after the first fire die forging, and the temperature continues to rise rapidly, reducing the time of the forging in the high temperature section, ensuring the structure (grain size) and performance of the forging.

[0037] Furthermore, after heat treatment (normalizing + high temperature tempering) of "Y" type AerMet100 structural steel die forgings, "Y" type AerMet100 structural steel die forgings are obtained. After heat treatment, sampling is carried out in the test area, and qualified structure and properties are obtained after quenching + cold treatment + tempering, thereby obtaining qualified "Y" type AerMet100 structural steel die forgings.

[0038] Further, the first threshold is 1030°C to 1040°C;

[0039] Further, the second threshold is -5°C to +5°C;

[0040] Further, the third threshold is 960°C to 1000°C;

[0041] Further, the fourth threshold is -10°C to +10°C;

[0042] Further, the fifth threshold is 1000°C to 1040°C;

[0043] Further, the sixth threshold is half of the holding time of the first fire;

[0044] Example:

[0045] The shape of the forging (such as Figure 1-1 As shown), the outline dimensions of this forging are 1350mm long, 415mm wide, and 211mm high. The forging is a broken line parting die (as shown Figure 1-2 As shown in the figure, the piston rod forging belongs to the fork-shaped forging. The forging consists of two parts. The front end is the fork-shaped area and the rear end is the rod area. The forging has a boss and a large cross-sectional size variation. The ratio of the maximum cross-sectional area to the minimum cross-sectional area is 5.3, and the maximum cross-sectional area is 0.048m 2 , the minimum cross-sectional area is 0.009m 2 The forked area of ​​the forging is about 450mm long, 415mm wide, and only 50 to 90mm thick. The forging is very difficult to form in this area. After the forging is heated by the bar Φ300×375, it is upset and squared along the streamline direction of the raw material bar on a 16MN free forging press to 832mm×290mm×110mm, and then a special tooling 1 (such as Figure 2 The "T" shaped intermediate slab is first obtained by partial thinning (as shown in FIG. Figure 2 2), using special tooling 2 (as shown in Figure 3 As shown) bend to obtain a "Y" shaped rough shape (as shown Figure 3 as shown) required size, trim thickness, and use a template or mold to check the "Y" shape (such as Figure 36). The parting surface of the "Y"-shaped rough shape is a flat parting surface. The "Y"-shaped rough shape is completed through 2 fires. The heating equipment is an electric furnace. The specific heating system is as follows: the first fire: heating to the preheating temperature of 850℃×90min, and then rapidly heating to 1030℃×105min; the second fire: heating to the preheating temperature of 850℃×50min, and then rapidly heating to 960℃×60(30)min, allowing the hot material to return to the furnace, and the insulation time of the hot material returning to the furnace is halved; after the "Y"-shaped rough shape is heated, the die forging is completed on a 365MN electric screw press, and the "Y"-shaped rough shape is completed through 2 fires. The specific heating system is as follows: the first fire: 960℃×60min, the second fire: 1030℃×60(30)min, allowing the hot material to return to the furnace between fires, and the insulation time of the hot material returning to the furnace is halved; finally, the "Y"-shaped AerMet100 structural steel die forging (as shown in FIG. Figure 1-1 shown).

[0046] More than 50 "Y"-shaped AerMet100 structural steel die forgings were produced using this process, with a product qualification rate of more than 99%. The "Y"-shaped AerMet100 structural steel die forgings have good mold filling, uniform structure, and a certain degree of performance surplus.

Claims

1. A method for forming a "Y" type AerMet100 structural steel die forging, characterized in that: include: The raw material bar is blanked to obtain a "Y" shaped rough shape; The "Y"-shaped rough shape is die forged to obtain the "Y" type AerMet100 structural steel die forgings.

2. The method according to claim 1, characterized in that The raw material bar is blanked to obtain a "Y" shaped rough shape, including: Upsetting, widening and thinning the raw material bars into rectangular plates; Put the rectangular plate into the lower mold, and use the upper flat anvil to make the blank to obtain a "T" shaped rough shape; The "T" shaped rough shape is placed in the lower tire mold, and the upper tire mold is used to make the blank to obtain the "Y" shaped rough shape; The "Y" type structural steel die forgings are obtained by die forging the "Y" shaped rough shape.

3. The method according to claim 1, characterized in that "Y" shaped and "Y" type structural steel die forgings use different parting methods, including: "Y"-shaped rough forgings use plane parting, and "Y"-type structural steel die forgings use broken line parting.

4. The method according to claim 1, characterized in that: The number of fires required for "Y"-shaped rough die forging is N, where N is less than or equal to 2.

5. The method according to claim 4, characterized in that When N=1, the "Y" type rough type is heated to the preheating temperature of 850℃, kept warm for a certain period of time, and then quickly heated to 1030℃~1040℃. The uniformity of the high temperature stage of the heating furnace is controlled within the range of -5℃~+5℃.

6. The method according to claim 4, characterized in that When N=2, First fire: "Y" type rough type is first heated to the preheating temperature of 850℃, kept warm for a certain period of time, and then quickly heated to 960℃~1000℃. The uniformity of the high temperature stage of the heating furnace is controlled within -10℃~+10℃; Second fire: After the first forging fire, the hot material is directly returned to the furnace without cooling, and the temperature is quickly raised to 1000℃~1040℃. It is kept warm for a certain period of time. The uniformity of the high temperature stage of the heating furnace is controlled within -5℃~+5℃.

7. The method according to claim 4, characterized in that Second fire: After the first forging, the hot material is directly returned to the furnace without cooling, and the temperature is quickly raised to 1000℃~1040℃, and kept warm for a certain period of time. The uniformity of the high temperature stage of the heating furnace is controlled within -5℃~+5℃, including: The hot material is returned to the furnace for the first time, and the first fire is heated to 960℃~1000℃ to match the small deformation; after the first fire, the forging is directly returned to the furnace with hot material, and the temperature continues to be rapidly increased to 1000℃~1040℃, and kept warm for a certain period of time, and the "Y" type AerMet100 structural steel die forgings are obtained by forging.

8. The method according to claim 7, characterized in that The above-mentioned certain insulation time is half of the insulation time of the first fire.

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