Splitting production and manufacturing method of high-strength alloy forge piece

Abstract

The invention relates to the technical field of alloy forge piece manufacturing, and discloses a high-strength alloy forge piece splitting production manufacturing method which comprises the following steps that 1, a to-be-machined alloy forge piece is split into a main body stress structure assembly, an auxiliary stress structure assembly and a supporting structure assembly according to structural attributes of all parts; 2, according to the set installing and welding sequence, first-step installing and welding are conducted on the main body stress structure assembly, then second-step installing and welding are conducted on the auxiliary stress structure assembly, and finally third-step installing and welding are conducted on the supporting structure assembly; step 3, carrying out nondestructive testing on the assembled and welded alloy forge piece, carrying out step 4 if no defect exists, and returning to the step 2 if the defect exists; 4, annealing the alloy forge piece, and then carrying out thermal refining; and step 5, detecting various mechanical properties. The forging difficulty is effectively reduced, materials needed by forging are reduced, the production cost is reduced, and the production efficiency is improved.

Description

Technical Field

[0001] The invention relates to the technical field of alloy forging manufacturing, and in particular to a splitting production method for high-strength alloy forgings. Background Art

[0002] As a high-strength alloy steel, 18Cr2Ni4W has been widely used in the field of high-end equipment manufacturing due to its excellent mechanical properties. This material not only has the characteristics of high strength and high toughness, but also exhibits good wear resistance and corrosion resistance. It is an ideal choice for manufacturing large, heavy-loaded and high-precision mechanical parts. In traditional manufacturing processes, the same type of forging products are generally produced by the method of overall forging and then machining the shape. For forging products with smaller size and simple shape, this production method can well meet production needs and ensure product quality and production efficiency.

[0003] However, when faced with forgings with large dimensions and complex shapes, since more margins need to be removed after the forgings are forged as a whole to achieve the size and shape required by the design, this leads to the complication of the machining process and the extension of the processing time. What is even more difficult is that for forgings with complex internal structures and narrow channels, the difficulty of machining increases significantly, and special tools and tooling equipment are often required, and sometimes even effective machining cannot be performed. This not only significantly increases production costs, but may also lead to an extension of the production cycle, resulting in a double waste of time and money. Summary of the invention

[0004] The present invention aims to provide a split production and manufacturing method for high-strength alloy forgings to solve the problem in the prior art that in the production of large-sized and complex-shaped forgings of 18Cr2Ni4W type high-strength alloy steel, the production is difficult and the production cost is high, resulting in low production efficiency.

[0005] To achieve the above object, the present invention adopts the following technical scheme: a split production and manufacturing method of high-strength alloy forgings. In this scheme, 18Cr2Ni4W high-strength alloy steel material is split forged and then welded together. The mechanical properties of the welded part after quenching and tempering treatment are not lower than those of the 18Cr2Ni4W material body. It is used to replace the manufacturing method of machining after integral forging of the material, improve production efficiency, and reduce production difficulty and cost. The manufacturing method comprises the following steps:

[0006] Step 1, splitting the alloy forging to be processed into main force-bearing structure components, auxiliary force-bearing structure components and supporting structure components according to the structural properties of each part of the alloy forging;

[0007] Step 2, according to the set welding sequence, firstly perform one-step welding on the main force-bearing structure components, then perform two-step welding on the auxiliary force-bearing structure components, and finally perform three-step welding on the supporting structure components;

[0008] Step 3, perform nondestructive testing on the alloy forgings after assembly welding, and proceed to step 4 if there are no defects. If there are defects, return to step 2;

[0009] Step 4, annealing and then tempering the welded alloy forging;

[0010] Step 5: testing various mechanical properties of the alloy forgings.

[0011] The principles and advantages of this solution are:

[0012] At present, for the manufacture of high-strength forgings, the overall forging method is generally preferred. This choice is mainly based on the following core reasons: First, overall forging can ensure that the forging has highly uniform and consistent mechanical properties as a whole, especially strength properties, which is crucial for many high-load or high-pressure application scenarios. Secondly, overall forging avoids the existence of welds, because in many concepts, welds are always regarded as a weak link in strength, especially when facing extreme stress conditions, welds may become potential risk points. Therefore, due to concerns about the strength of the welds, high-strength products are generally not considered for split assembly welding.

[0013] However, this solution abandons this technical prejudice. By conducting an in-depth analysis of the forging structure, it not only considers the overall mechanical performance requirements, but also evaluates the stress distribution and potential failure modes of each part, and cleverly achieves the reasonable splitting of the structure. Under the premise of ensuring that each structural component can meet the strength requirements, the strength of the weld is effectively improved through fine process measures such as preheating before welding and heat preservation during welding, so that the strength of the product after assembly welding can be guaranteed. This innovation not only greatly reduces the materials required for overall forging, improves production efficiency, but also significantly reduces manufacturing costs.

[0014] Furthermore, the main force-bearing structure component is a part that provides the main frame structure and connection positioning of the forging; the auxiliary force-bearing structure component is a part that is positioned according to the main force-bearing structure component and makes the forging as a whole; the supporting structure component is a part that strengthens the shape of the forging.

[0015] Furthermore, in step 2, gas shielded welding is adopted and corresponding welding parameters are set.

[0016] Furthermore, in step 2, the following sub-steps are also included:

[0017] Step 2.1, one-step welding, using the positioning and blocking structure to weld the main force-bearing structural components to form a main frame;

[0018] Step 2.2, two-step welding, positioning according to the main frame formed after the first step welding, positioning and welding each auxiliary force-bearing structure component on the main frame to form an integral forging;

[0019] Step 2.3, three-step welding, positioning welding is performed on each supporting structure component according to the shape of the overall forging to obtain the alloy forging.

[0020] Furthermore, in step 2, the welding part is also preheated before welding, and the preheating temperature is set to 200°C to 250°C.

[0021] Furthermore, in step 2, it also includes taking insulation measures during the welding process. The insulation measures are: if the temperature of the workpiece is lower than 200°C during the welding process, the workpiece is immediately placed in a heat treatment furnace for supplementary heating, and after welding, the product is wrapped with insulation cotton to keep it warm and slowly cool to room temperature.

[0022] Furthermore, the welding parameters include: welding current 220A-260A, welding voltage 25V-29V, gas flow rate 20L / min-25L / min, and the temperature between each layer is controlled at 200°C-250°C.

[0023] Furthermore, in step 3, ultrasonic and magnetic powder are used for non-destructive testing.

[0024] Furthermore, in step 4, the quenching and tempering treatment is overall quenching and tempering, which improves the overall strength, plasticity and toughness of the product, thereby making it have good comprehensive mechanical properties.

[0025] Furthermore, the shielding gas uses carbon dioxide. By using carbon dioxide with a purity of ≥99.99% as a shielding medium, harmful gases such as oxygen and water vapor around the molten pool and weld can be effectively removed to form a shielding gas cover to prevent the generation of welding defects such as oxidation, contamination and pores, reduce the occurrence of quality problems such as thermal cracks and inclusions, and thus improve welding quality. BRIEF DESCRIPTION OF THE DRAWINGS

[0026] Figure 1 The present invention is a schematic diagram of the process of splitting and producing a high-strength alloy forging.

[0027] Figure 2 It is a structural schematic diagram of a method for splitting 18Cr2Ni4W forging products in a method for splitting and manufacturing high-strength alloy forgings of the present invention. DETAILED DESCRIPTION

[0028] The following is further described in detail through specific implementation methods:

[0029] The reference numerals in the drawings of the specification include: a first main body component 1 , a second main body component 2 , a third main body component 3 , a fourth auxiliary component 4 , a fifth main body component 5 , a sixth auxiliary component 6 , a seventh support component 7 , and an eighth support component 8 .

[0030] Embodiment 1

[0031] This embodiment is basically as shown in the attached Figure 1 As shown, a split production and manufacturing method of high-strength alloy forgings is to forge 18Cr2Ni4W high-strength alloy steel materials separately and then weld them together, and ensure that the mechanical properties of the welds after quenching and tempering are not lower than those of the 18Cr2Ni4W material body, so as to reduce the difficulty and cost of welding and improve the forging efficiency. This manufacturing method includes the following steps:

[0032] S1, splitting the alloy forging to be processed according to the structural properties of each part of the alloy forging, and splitting it into main force-bearing structure components, auxiliary force-bearing structure components and supporting structure components based on components.

[0033] In this embodiment, the division of the split components is mainly based on reducing the difficulty and workload of forging and welding, and the components are divided into the smallest units and forged in the same batch with the same size. After forging, the components are welded in place at one time, and there is no intermediate state of welding each other and then welding the whole, which reduces the welding process, reduces the difficulty of welding, and improves the welding efficiency.

[0034] Specifically, the alloy forgings to be forged are divided according to their structural properties, wherein the main force-bearing structural components are the parts that provide the main frame structure and connection positioning of the forgings, the auxiliary force-bearing structural components are the parts that are positioned according to the main force-bearing structural components and make the forgings integrally formed, and the supporting structural components are the parts that strengthen the shape of the forgings. In this embodiment, the divided structural components are the smallest units.

[0035] The specific splitting method is explained by taking 18Cr2Ni4W forging products as an example, as shown in the attached Figure 2 As shown, when splitting, the main body is divided into three categories according to the product structure and usage requirements, namely the main load-bearing structure components, auxiliary load-bearing structure components and supporting structure components.

[0036] Among them, the main force-bearing structure component is the part that will be connected with other products later. When ensuring the welding quality, the positioning dimensions must also be ensured. According to the main frame structure of the forging and the connection and positioning parts, the main force-bearing structure component can be divided into the first main component 1, the second main component 2, the third main component 3 and the fifth main component 5 as shown in the figure. The auxiliary force-bearing structure component can be positioned and welded according to the main force-bearing structure under the premise of ensuring the welding quality. Therefore, it is divided into the fourth auxiliary component 4 and the sixth auxiliary component 6 according to the positioning of the main force-bearing structure component and the part that constitutes the overall forming of the forging. The support structure component is a rib plate structure. After the main and auxiliary structures are completed, welding can be performed at the corresponding positions. Therefore, it can be divided into the seventh support component 7 and the eighth support component 8 as shown in the figure.

[0037] After the division is completed, the components of the same batch are forged and formed, and then S2 group welding is carried out.

[0038] S2, according to the set welding sequence, firstly perform one-step welding on the main load-bearing structure components, then perform two-step welding on the auxiliary load-bearing structure components, and finally perform three-step welding on the supporting structure components.

[0039] In this embodiment, the group welding adopts gas shielded arc welding (GMAW), the welding wire brand can be selected as ER130S-G, and appropriate welding parameters are set. In this embodiment, the welding parameters include: welding current 220A ~ 260A, welding voltage 25V ~ 29V, gas flow rate 20L / min ~ 25L / min, and each interlayer temperature is controlled at 200℃ ~ 250℃.

[0040] Before welding, the welding part needs to be preheated, and the preheating temperature should be well controlled to increase the initial temperature of the weld to slow down the cooling rate of the weld joint after welding, reduce the temperature difference between the welded workpieces in the welding area, reduce welding stress, and further reduce the generation of welding cracks, thereby improving the quality of the weld. In this embodiment, the preheating temperature is set to 200°C to 250°C. At the same time, insulation measures are taken during the welding process, that is, if the workpiece temperature is lower than 200°C during the welding process, the workpiece is immediately placed in a heat treatment furnace for supplementary heating to keep the temperature of the welding part stable, so as to prevent welding defects caused by rapid temperature changes, effectively reduce the welding time, and ensure the stability and consistency of the welding quality.

[0041] In this embodiment, the welding sequence mainly includes the following sub-steps:

[0042] Step 2.1, one-step welding, using the positioning and blocking structure to weld the main force-bearing structural components to form a main frame; that is, first use the positioning and blocking to weld the first main component 1, the second main component 2, the third main component 3 and the fifth main component 5 together to ensure the main structure and positioning of the product.

[0043] Step 2.2, two-step welding, positioning according to the main frame formed after the first step of welding, positioning and welding each auxiliary force-bearing structure component on the main frame to form an integral forging. That is, on the completed main frame, positioning according to the frame position, the fourth auxiliary component 4 and the sixth auxiliary component 6 are welded to the main frame to form the product as a whole.

[0044] Step 2.3, three-step welding, according to the shape of the overall forging, each support structure component is positioned and welded to obtain an alloy forging. Finally, according to the shape of the formed product, the seventh support component 7 and the eighth support component 8 and other small components such as the reinforcing rib plate are welded to complete the overall welding process of the alloy forging at one time.

[0045] S3, perform nondestructive testing on the alloy forgings after assembly welding, and proceed to S4 if there are no defects. If there are defects, return to S2.

[0046] In this embodiment, ultrasonic wave and magnetic powder are used for post-weld non-destructive testing. If the test is qualified, that is, there is no defect, the process proceeds to S4. If there is a defect, S2 is repeated and repair welding is performed again.

[0047] S4, annealing and tempering treatment of the alloy forging after welding.

[0048] In this embodiment, the quenching and tempering treatment is an overall quenching and tempering, including two steps of quenching and high temperature tempering. First, the welded product is heated to above the critical temperature to completely transform it into austenite. In this embodiment, the critical temperature is 850°C. After being kept warm for more than 8 hours, it is quickly cooled to increase the hardness of the product. Then the product is reheated to 500°C and kept warm for 12 hours, and then air-cooled to room temperature to eliminate the internal stress generated by quenching and increase toughness and strength. After quenching and tempering treatment, the product can further improve its strength, plasticity and toughness, improve its overall comprehensive mechanical properties, and be more conducive to subsequent mechanical processing.

[0049] S5, test the mechanical properties of alloy forgings.

[0050] The performance requirements of the alloy forgings after integral forging and tempering in the prior art and the alloy forgings after tempering manufactured by the forging method adopted in this scheme were tested for various mechanical properties, and the test results obtained are shown in Table 1 below:

[0051] Table 1

[0052]

[0053] As can be seen from Table 1 above, the mechanical properties of the 18Cr2Ni4W high-strength alloy steel material after split forging and welding in this scheme are not lower than those of the 18Cr2Ni4W material after overall forging and tempering, and can meet the performance requirements and directly replace the existing manufacturing method of overall forging and machining. It also greatly reduces material consumption during the forging process, greatly reduces the difficulty of machining in the subsequent machining process, shortens the machining time, and reduces the overall production cost.

[0054] At present, for the manufacture of high-strength forgings, the overall forging method is generally preferred. This choice is based on the consideration of ensuring the strength of the forgings, while the method of splitting forging and then welding is rejected because it is believed that the weld cannot fully meet the strength standard. In this embodiment, under the premise of ensuring the mechanical properties requirements of the weld, the forging is split into multiple structural components, each of which can independently meet the strength requirements, and can work together after welding to achieve the overall strength standard. Split forging can effectively reduce raw material consumption, reduce forging difficulty, and reduce corresponding production costs, and has strong competitiveness in manufacturing large products with the same material.

[0055] The above is only an embodiment of the present invention, and the common knowledge such as the known specific technical solutions and / or characteristics in the solution is not described in detail here. It should be pointed out that for those skilled in the art, without departing from the technical solution of the present invention, several modifications and improvements can be made, which should also be regarded as the protection scope of the present invention, and these will not affect the effect of the implementation of the present invention and the practicality of the patent. The scope of protection required by this application shall be based on the content of its claims, and the specific implementation methods and other records in the specification can be used to interpret the content of the claims.

Claims

1. A method for splitting and manufacturing high-strength alloy forgings, characterized in that: The following steps are involved: Step 1, splitting the alloy forging to be processed into main force-bearing structure components, auxiliary force-bearing structure components and supporting structure components according to the structural properties of each part of the alloy forging; Step 2, according to the set welding sequence, firstly perform one-step welding on the main force-bearing structure components, then perform two-step welding on the auxiliary force-bearing structure components, and finally perform three-step welding on the supporting structure components; Step 3, perform nondestructive testing on the alloy forgings after assembly welding, and proceed to step 4 if there are no defects. If there are defects, return to step 2; Step 4, annealing and then tempering the welded alloy forging; Step 5: testing various mechanical properties of the alloy forgings.

2. The method for splitting and manufacturing a high-strength alloy forging according to claim 1, characterized in that: The main force-bearing structure component is a part that provides the main frame structure and connection positioning of the forging; the auxiliary force-bearing structure component is a part that is positioned according to the main force-bearing structure component and makes the forging as a whole; the supporting structure component is a part that strengthens the shape of the forging.

3. The method for splitting and manufacturing a high-strength alloy forging according to claim 1, characterized in that: In step 2, gas shielded welding is used and corresponding welding parameters are set.

4. The method for splitting and manufacturing a high-strength alloy forging according to claim 1, characterized in that: In step 2, the following sub-steps are also included: Step 2.1, one-step welding, using the positioning and blocking structure to weld the main force-bearing structural components to form a main frame; Step 2.2, two-step welding, positioning according to the main frame formed after the first step welding, positioning and welding each auxiliary force-bearing structure component on the main frame to form an integral forging; Step 2.3, three-step welding, positioning welding is performed on each supporting structure component according to the shape of the overall forging to obtain the alloy forging.

5. The method for splitting and manufacturing a high-strength alloy forging according to claim 1, characterized in that: In step 2, the welding part is also preheated before welding, and the preheating temperature is set to 200°C to 250°C.

6. The method for splitting and manufacturing a high-strength alloy forging according to claim 1, characterized in that: In step 2, it also includes taking insulation measures during the welding process. The insulation measures are: if the temperature of the workpiece is lower than 200°C during the welding process, the workpiece is immediately placed in a heat treatment furnace for supplementary heating. After welding, the product is wrapped with insulation cotton to keep it warm and slowly cool to room temperature.

7. The method for splitting and manufacturing a high-strength alloy forging according to claim 3, characterized in that: The welding parameters include: welding current 220A-260A, welding voltage 25V-29V, gas flow 20L / min-25L / min, and the temperature between each layer is controlled at 200°C-250°C.

8. The method for splitting and manufacturing a high-strength alloy forging according to claim 1, characterized in that: In step 3, non-destructive testing is performed using ultrasonic and magnetic particle.

9. The method for splitting and manufacturing a high-strength alloy forging according to claim 1, characterized in that: In step 4, the heat treatment is an overall heat treatment.

10. The method for splitting and manufacturing a high-strength alloy forging according to claim 3, characterized in that: The protective gas is carbon dioxide, and its purity is ≥99.99%.

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