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mild steel pipe

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mild steel pipe
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Manual inspection of mild steel pipes

Date:2024-01-17View:271Tags:mild steel pipe
Manual inspection of mild steel pipes

1. Preparations before the inspection

1) The inspector on duty should prepare the paint and high-temperature chalk used for the inspection and marking of the class in preparation for application.

mild steel pipe

2) Check whether the outer surface lighting and the inner surface inspection light are normal. If there is any problem, the special seamless steel pipe factory should be notified in time, and the dispatching room of the special mild steel pipe factory will assign an electrician to repair it. If the lighting for inspection of the exterior surface is not on at night, the inspection shall not be carried out.

3) Check the vernier caliper, wall thickness micrometer and other measuring tools, whether the measuring tools are within the specified validity period of calibration, and whether the wall thickness micrometer and the vernier caliper zero position can be aligned.

4) Succession inspectors should carefully check the work records to understand the main quality problems and remaining problems; carefully review the production plan and process notices or corresponding standards, and be aware of the varieties, specifications and quality requirements of the steel pipes to be inspected by this class.

2. Conditions for seamless pipe inspection

1) Before the inspection of each furnace of steel pipes, there must be a production flow card transferred from the finishing operation area.

2) The inspector must check whether the production flow card is consistent with the production plan and the physical contract number, heat number, standard, specification, and steel grade. If there is any objection, he should contact the squad leader in the finishing operation area of the special seamless steel pipe factory to find out the reason. , the reason shall not be checked.

3. Steel pipe inspection items and methods

1) The quality of the outer surface of the steel pipe is visually inspected one by one according to the requirements of the corresponding standards; the quality of the inner surface is visually inspected one by one according to the requirements of the corresponding standard using the inner surface inspection lamp.

2) Measurement of the outer diameter and wall thickness of the steel pipe: the outer diameter of the steel pipe is measured at the pipe end with a vernier caliper, and the two outer diameter values D1 and D2 should be perpendicular to each other. The wall thickness of the steel pipe is measured at the end of the pipe with a wall thickness micrometer, and the wall thickness value at four points is evenly measured. (D1, D2 are two outer diameter values, S1, S2, S3, S4 are four-point wall thickness values.)

3) When there is a bending requirement for the pipe, the bending degree must be checked visually. When a row of steel pipes is squeezed together and there is obvious bending of the pipe body and a gap appears, the production personnel should be notified, and the bent pipe should be removed for re-correction or discarded; If there is any objection when the bending of the pipe body is not serious, the pipe should be removed, and the bending degree of the steel pipe should be measured by the wire drawing method or the ruler method.

4. Identification of steel pipe quality inspection

1) For cutting and repairing products, steel pipes whose end defects need to be removed, when the removed part is within 0.6 meters from the end, high-temperature chalk should be used to draw a line and mark the defect name and mark on the part to be cut, and a broken line should be drawn at the cut part. Covers the entire cylindrical surface of the pipe segment as much as possible.

2) When the defect to be removed at the end is greater than 0.6 meters, high temperature chalk should be used to draw a polyline at the pipe end, and the distance of the cutting position and the name of the defect should be marked with an arrow knot. The polyline drawn should cover the entire cylindrical surface of the pipe section as much as possible.

3) For waste products, mark “Ä” and mark the defect name within 0.5 meters of the pipe end.

4) For the repaired products that have been inspected, a "™" mark can be drawn on the defect of the repaired grinding. After the repaired and grounded products are qualified, a "V" mark can be marked with the team. If the repaired and grounded products are unqualified, a "™" mark can be drawn at the pipe end 0.5 meters. Mark with "Ä" and dispose of it as waste.

5) The steel pipe that has been re-cut, ground, and straightened should be re-inspected.

5. Frequency of random inspection of steel pipe geometric dimensions

When taking over and replacing the first 10 steel pipes of the specification, the geometric dimensions must be measured at the required measuring points; when about 1/2 of the steel pipes for each furnace are inspected, the geometric dimensions of 10 steel pipes shall be sampled, and the measured record value of the geometric dimensions of each furnace shall not be less than 10 60 values for branch pipes.

6. Completion of quality records

For each furnace of steel pipes that has been inspected or needs to be handed over but not inspected, the "Finished (Semi-Finished) Inspection Record" must be filled in. The handwriting should be clear when filling in the record, no scribbling is allowed, the recorded data should be accurate, and the geometric dimensions should be sampled. The data should be recorded with the test, no memoirs should be written, and the person who needs to modify the record should sign the name. The inspection records are regularly collected by the statistician or judge in the station, and sorted and archived by the statistician.

7. Transmission of abnormal quality information

When the inspector finds that the same defect occurs continuously, he should notify the shift schedule in time and ask him to find the cause and eliminate the fault.


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