The essence of high-temperature temper brittleness of seamless pipes is generally considered to be the result of the segregation of impurity elements such as phosphorus, tin, and antimony at the prior austenite grain boundaries, resulting in the embrittlement of the grain boundaries.

In the process of pile driving, the top of the pipe pile is prone to concrete drop angle, cracking, collapse or even the steel bar on the top of the pile is completely exposed and damaged. What are the reasons and preventive measures for this phenomenon?

By heating the seamless steel pipe to about 550~850 °C, after a constant temperature for one time, the carbon metal and other various alloys are uniformly dissolved in the austenite. , through the rapid cooling of quenching water, carbon and other alloys have no time to precipitate, and pure austenite structure is obtained, which is called solid solution treatment.

With the advancement of welding and inspection technology, the quality of welds has been continuously improved, the varieties and specifications of welded steel pipes have been increasing, and seamless steel pipes have been replaced in more and more fields.So what should be paid attention to in the installation process of welded pipes?

When cold drawn seamless pipe is bent and deformed, they can continue to be used as long as they can be corrected, otherwise it will affect the use of cold drawn seamless tubing.

Seamless pipe without quenching hardness less than HRC28, relatively soft, not wear-resistant; quenched hardness can be (note that it can be) greater than HRC55, wear resistance is better, but this is a small cross-section, the cross-section is slightly larger, the hardness obtained will be reduced.