Seamless steel tubes are more cumbersome and more rigorous in the production process. After the seamless steel pipe is produced, it is necessary to carry out certain tests. Do you know the flat steel pipe flattening test method and steps?First, the flattened sample: 1. The sample is cut from any part of the seamless steel tube that has passed the visual inspection. The sample should be the full-loaded pipe section of the pipe product.
2. The length of the sample should be no less than 10mm, but not more than 100mm. The edges of the specimen are allowed to be rounded or chamfered by sputum or other means. Note: If the test results meet the test requirements, the edges of the specimen may not be rounded or chamfered. 3. If you want to carry out the tube end of a full length tubeDuring the test, the cut should be perpendicular to the longitudinal axis of the tube at the end of the tube from the end of the tube, and the cutting depth should be at least 80% of the outer diameter.
3. Test equipment: The test can be carried out on a universal testing machine or a pressure testing machine. The test machine shall be equipped with two upper and lower parallel pressure plates, and the width of the parallel pressure plate shall exceed the width of the sample after crushing, that is, at least 1.6D. The length of the platen is not less than the length of the sample. The testing machine has the ability to flatten the sample to a specified platen distance. The pressure plate should have sufficient stiffness. And can control the rate range required by the test.
Third, the test conditions and operating procedures: 1, the test should generally be carried out in the room temperature range of 10 ° C ~ 35 ° C. For tests required to be carried out under controlled conditions, the test temperature shall be 23 ° C ± 5 ° C. The flattening speed of the sample may be 20-50 mm / min. In the event of a dispute, the rate of movement of the platen shall not exceed 25 mm / min.
3. According to the relevant standards, or the agreement between the two parties to determine the platen distance H, H is the distance between the two pressure plates under the force (unit mm); t is the nominal pipe wall thickness (unit mm); after the flattened sample Inner width (unit: mm); D is the nominal outer diameter of the steel pipe (unit: mm); a is a constant, the general value specified by the relevant standard is taken as 0.07, 0.08, 0.09 3.