Flaw detection method of stainless steel forge piece

Abstract

The invention discloses a flaw detection method for stainless steel forgings, and relates to the field of flaw detection of stainless steel parts. The process comprises the following steps: pretreatment: heating a stainless steel forge piece at the temperature of 70-90 DEG C for 3-8 minutes; pickling: pickling the heated stainless steel forge piece with a stainless steel pickling solution, and taking out the stainless steel forge piece when the stainless steel surface is silvery white after rust and impurities on the stainless steel surface are removed; washing: washing the pickled stainless steel forge piece with water to remove the residual pickling solution on the surface of the stainless steel; according to the method, the flaw detection process and the acid pickling process are combined, no additional flaw detection equipment is needed, the equipment investment and the operation cost are greatly reduced, flaw detection and acid pickling are completed in the same process step, and the additional operation cost and the labor cost are reduced.

Description

Technical Field

[0001] The invention relates to the field of flaw detection of stainless steel parts, and in particular to a flaw detection method for stainless steel forgings. Background Art

[0002] After the stainless steel parts are processed, they need to be inspected according to their use needs to obtain the number, shape and type of surface defects, and use this to determine whether the stainless steel parts meet the requirements. However, the existing stainless steel flaw detection methods generally use ultrasonic flaw detection, radiographic flaw detection, penetrant flaw detection and other methods to detect the defects of stainless steel parts, but these detection methods still have the defects of high cost and low efficiency when used in industrial production. Summary of the invention

[0003] In view of the defects in the prior art, the present application proposes a method for flaw detection of stainless steel forgings. In the process of implementing the embodiments of the present application, the inventors found that after the stainless steel parts are forged, they need to go through the final pickling process before flaw detection operations can be performed to determine whether the processed stainless steel parts meet the standards; and the inventors found during the pickling process that some of their stainless steel forgings have residual black ash and attachments after pickling, and these residual black ash and attachments often remain in the defective areas on the stainless steel surface. Therefore, the inventors adjusted the stainless steel pickling process accordingly, so that the accuracy of defect detection through the pickling process is greatly improved.

[0004] The present invention solves the technical problem by adopting the following technical solutions.

[0005] A method for flaw detection of stainless steel forgings comprises the following steps: Pretreatment: Heat the stainless steel forgings at 70-90°C for 3-8 minutes; Pickling: Use stainless steel pickling liquid to pickle the heated stainless steel forgings. When the rust and impurities on the stainless steel surface are removed and the surface is silvery white, take out the stainless steel forgings. Cleaning: Wash the stainless steel forgings after pickling with water to remove the pickling liquid remaining on the stainless steel surface; Inspection: Observe the cleaned stainless steel forgings to check whether there is any residual black ash and attachments in the local area. If any residual black ash and attachments are found in the local area, mark it as a defective location and record the location and shape of the point.

[0006] Furthermore, in the pretreatment, the stainless steel forgings are mixed with water and heated at a temperature of 75-85°C for 4-6 minutes, so that the surface of the parts can be better activated and the passivation reaction rate can be accelerated.

[0007] Furthermore, the specific method of the pre-processing step is as follows: Put the stainless steel forgings into a container and add water into the container, wherein the volume ratio of the stainless steel forgings is less than or equal to 40, and heat the water in the container to a temperature of 78-82° C. for 5 minutes.

[0008] Furthermore, the stainless steel pickling solution is an organic acid pickling solution, and the pickling time is 15-25 minutes, so that it can remove rust and impurities on the surface of the stainless steel, making the stainless steel surface silvery white without spots or black spots; Preferably, the stainless steel pickling liquid is THIF-126 stainless steel pickling liquid, and the pickling time is 18-22 minutes. Generally, the rust and impurities on the surface of the stainless steel can be removed within this time period, but there will still be residues at the defects. Therefore, the location and shape of the defects on the stainless steel parts can be judged by this.

[0009] Furthermore, in the cleaning step, running water is used for cleaning for 1-3 minutes to make it easier to clean.

[0010] Preferably, a high-pressure water gun can be used to further rinse the stainless steel forgings in the detection step. During the rinsing process, check whether there is any residual black ash and attachments in the local area of ​​the stainless steel forgings and record them. Stainless steel parts often need to be further rinsed with a high-pressure water gun after the cleaning time, so the defects of the stainless steel forgings can be detected during the rinsing process.

[0011] Furthermore, the stainless steel forging is an austenitic stainless steel forging, that is, the method can be used for defect detection of austenitic stainless steel forgings.

[0012] Furthermore, the stainless steel forging is a forged stainless steel forging to be pickled.

[0013] Technical effects: 1. This application combines the flaw detection process with the pickling process, without the need for additional flaw detection equipment, which greatly reduces equipment investment and operating costs, and completes flaw detection and pickling in the same process step, reducing additional operating and labor costs.

[0014] 2. In the present application, flaw detection is automatically completed during the pickling process, which avoids the independent steps of the flaw detection process and realizes the rapid appearance of defects without the need for complicated subsequent detection steps, thereby significantly improving production efficiency.

[0015] 3. The method of this application has a significant defect location capability for surface and shallow defects, so that the staff can clearly mark the defect location for subsequent analysis and processing.

[0016] 4. No radiation-risk detection methods such as X-rays are used, so the operation is safer, and the formula of the pickling solution can use environmentally friendly ingredients to reduce harm to the environment and operators.

[0017] 5. This solution can be directly integrated into the existing stainless steel pickling process without large-scale transformation of the existing production line, and it has good process integration. DETAILED DESCRIPTION

[0018] After stainless steel parts are processed, they need to be inspected to determine whether they meet the quality requirements. However, existing methods such as ultrasonic flaw detection, radiographic flaw detection, and penetrant flaw detection have the following defects in industrial production: 1. High cost: expensive equipment and labor costs, 2. Low efficiency: flaw detection as a separate process takes extra time, 3. Environmental impact: For example, chemicals used in penetrant flaw detection may cause environmental pollution. To address these issues, this application proposes a technical solution that integrates flaw detection functions in the pickling process to reduce costs, improve efficiency, and meet environmental protection requirements.

[0019] The technical solution of the present invention is further explained and illustrated by specific embodiments below.

[0020] Embodiment 1: A method for flaw detection of a stainless steel forging, comprising the following steps: Pretreatment: Place the forged stainless steel forgings to be pickled and water in a volume ratio of 2:8 into a container and heat to 70°C for 8 minutes to better activate the surface of the parts and accelerate the passivation reaction rate; Pickling: Put the heated stainless steel forgings into the passivation tank and use stainless steel pickling solution for pickling. When the rust and impurities on the stainless steel surface are removed and the surface is silvery white, take out the stainless steel forgings; Cleaning: Wash the pickled stainless steel forgings with running water for 3 minutes to remove the pickling liquid remaining on the stainless steel surface; Detection: Use a high-pressure water gun to further rinse the stainless steel forgings. During the rinsing process, check whether there is any residual black ash and attachments on the stainless steel forgings, and record them. Stainless steel parts often need to be further rinsed with a high-pressure water gun after the cleaning time, so the defects of the stainless steel forgings can be detected during the rinsing process.

[0021] Embodiment 2: A method for flaw detection of a stainless steel forging, comprising the following steps: Pretreatment: Place the forged stainless steel forgings to be pickled and water in a volume ratio of 4:6 into a container and heat to 85°C for 4 minutes to better activate the surface of the parts and accelerate the passivation reaction rate; Pickling: Put the heated stainless steel forgings into the passivation tank and use organic acid stainless steel pickling solution for pickling for 15-25 minutes. When the rust and impurities on the stainless steel surface are removed and the surface is silvery white, take out the stainless steel forgings; Cleaning: Wash the pickled stainless steel forgings with running water for 3 minutes to remove the pickling liquid remaining on the stainless steel surface; Detection: Use a high-pressure water gun to further rinse the stainless steel forgings. During the rinsing process, check whether there is any residual black ash and attachments on the stainless steel forgings, and record them. Stainless steel parts often need to be further rinsed with a high-pressure water gun after the cleaning time, so the defects of the stainless steel forgings can be detected during the rinsing process.

[0022] Embodiment 3: A method for flaw detection of stainless steel forgings, comprising the following steps: Pretreatment: Place the forged austenitic stainless steel forgings to be pickled and water in a volume ratio of 3:7 into a container and heat to 80°C for 5 minutes to better activate the surface of the parts and accelerate the passivation reaction rate; Pickling: Put the heated stainless steel forgings into the passivation tank and pickle them with THIF-126 stainless steel pickling solution for 20 minutes. When the rust and impurities on the stainless steel surface are removed and the surface is silvery white, take out the stainless steel forgings; Cleaning: Wash the pickled stainless steel forgings with running water for 3 minutes to remove the pickling liquid remaining on the stainless steel surface; Detection: Use a high-pressure water gun to further rinse the stainless steel forgings. During the rinsing process, check whether there is any residual black ash and attachments on the stainless steel forgings, and record their location and shape. Stainless steel parts often need to be further rinsed with a high-pressure water gun after the cleaning time, so the defects of the stainless steel forgings can be detected during the rinsing process.

[0023] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art who is familiar with the technical field can easily think of changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A method for flaw detection of stainless steel forgings, characterized in that: The steps include: Pretreatment: Heat the stainless steel forgings at 70-90°C for 3-8 minutes; Pickling: Use stainless steel pickling liquid to pickle the heated stainless steel forgings. When the rust and impurities on the stainless steel surface are removed and the surface is silvery white, take out the stainless steel forgings. Cleaning: Wash the stainless steel forgings after pickling with water to remove the pickling liquid remaining on the stainless steel surface; Inspection: Observe the cleaned stainless steel forgings to check whether there is any residual black ash and attachments on the parts.

2. A flaw detection method for stainless steel forgings according to claim 1, characterized in that: In the pretreatment, the stainless steel forgings are mixed with water and heated at a temperature of 75-85°C for 4-6 minutes.

3. A flaw detection method for stainless steel forgings according to claim 2, characterized in that: The specific method of the pre-treatment step is as follows: Put the stainless steel forgings into a container and add water into the container, wherein the volume ratio of the stainless steel forgings is less than or equal to 40, and heat the water in the container to a temperature of 78-82° C. for 5 minutes.

4. A flaw detection method for stainless steel forgings according to claim 1, characterized in that: The stainless steel pickling solution is an organic acid pickling solution, and the pickling time is 15-25 minutes.

5. A flaw detection method for stainless steel forgings according to claim 4, characterized in that: The stainless steel pickling liquid is THIF-126 stainless steel pickling liquid, and the pickling time is 18-22 minutes.

6. A flaw detection method for stainless steel forgings according to claim 1, characterized in that: During the cleaning step, use running water for 1-3 minutes.

7. A flaw detection method for stainless steel forgings according to claim 6, characterized in that: In the detection step, a high-pressure water gun can be used to further rinse the stainless steel forgings. During the rinsing process, check whether there is any residual black ash and attachments on the stainless steel forgings, and record them.

8. A flaw detection method for stainless steel forgings according to claim 1, characterized in that: The stainless steel forging is an austenitic stainless steel forging.

9. A flaw detection method for stainless steel forgings according to claim 1, characterized in that: The stainless steel forging is a forged stainless steel forging to be pickled.