Seamless steel pipe is more boring and strict in the production process. Seamless steel tube is one of the most important steel tubes. It is necessary to carry out repeated tests, development and production in the production process, to manufacture the properties of pipes and the use of seamless steel pipes, and to make full use of their various applications and use of engineering and treatment. In the process of development and production of seamless steel pipe, some experiments are needed. Here, the main topic is the decompression flat test, which is the research of seamless steel pipe factory on seamless steel pipe physical and chemical workroom, and more important test. What are the common methods and procedures for testing?

Flatness test aims to test the ultimate plastic deformation ability and collapse deformation of seamless steel tube under given conditions, without crack defects.  The principle is to apply the length of seamless steel tube to the specified length of sample or seamless steel tube end. According to the pressure, the distance between the two plates under the action of force can reach the value specified in the relevant product standards.

First, smooth samples
1. Cut the sample from any part of seamless steel pipe by visual inspection. The sample shall be the full-load pipe part of the pipeline product.
2. Sample length should not be less than 10 mm, but not more than 100 mm.  Sample edges are allowed to be chamfered or chamfered by yttrium or other methods. Note: If the test results meet the test requirements, no fillets or chamfers can be made on the edge of the sample.
3. If you want to test the end of a full-length pipeline, cut along the longitudinal axis of the pipeline along the length of the pipeline. Cutting depth should be at least 80% of outer diameter.


2. Testing 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 parallel upper and lower pressure plates. The width of parallel cardboard should exceed the width of plane sample, i.e. at least 1.6D. The length of the plate is not less than that of the sample. The tester can flatten the sample to a specified distance. The board should be rigid enough. You can control the speed range required for testing.