API 5L steel pipe is a type of low carbon steel pipe that is widely used in structural pipes and fluid pipes because of its ease of processing. However, a common problem with API 5L steel pipes is that there are pits and pits on the surface, or they are easy to crack during later bending, flattening and other processing, which affects the quality of customers' products.
These problems are also currently unable to be solved by many API seamless steel pipe manufacturers, but steel pipes can be solved, the main reasons are as follows: In addition to carbon elements and a certain amount of silicon and manganese for deoxidation, API-free steel pipes do not contain other alloying elements (except residual elements), so it is particularly easy to cause surface damage during perforation. Dimples.
API 5L steel pipe is a line pipe that belongs to the American Petroleum Standard. Line pipe is used to transport oil, steam, and water extracted from the ground to oil and natural gas industry enterprises through pipeline pipes. Line pipes include seamless pipes and welded steel pipes, and their pipe ends have flat ends. , with threaded end and socket end; its connection methods are end welding, coupling connection, socket connection, etc.
The quality inspection of API 5L steel pipes is particularly important. Generally, the ultrasonic testing of API steel pipes is divided into two types: online and manual. The online ultrasonic flaw detection wave of API steel pipes is installed in the production line.
The continuously produced steel pipes are inspected online. Once defects appear, they will be inspected online. An alarm will be issued because the online ultrasonic testing equipment is automatic, so omissions and false alarms may occur during the testing process. Therefore, manual ultrasonic testing is required after each batch of API steel pipes comes off the line.
API 5L steel pipes use high-frequency welding, so the common welding defect is lack of fusion. And because its current and voltage are controlled by machines, the phenomenon of lack of fusion in a quantity of API steel pipes usually takes a long time.
Therefore, steel pipe manufacturers recommend that API steel pipe probe detection and judgment are easier. But testers must be required to test quickly. If the speed is slow, it will affect production efficiency and easily lead to an increase in the amount of steel pipe scrap.