Seamless steel pipe
appeared more than 100 years ago. It is a great invention. The appearance of seamless steel pipe has provided a lot of convenience for all walks of life in our country.
Seamless steel pipe is a round, square and rectangular steel with a hollow section and no joints around it. It is made of steel ingots or solid tube blanks through perforation to make capillaries, and then hot-rolled, cold-rolled or cold-drawn.
The production of seamless steel pipes has a history of nearly 100 years. The German Mannismann Brothers first invented the two-roll cross-rolling piercing machine in 1885, and the periodic tube rolling mill in 1891. After that, various extension machines such as continuous pipe rolling mills and pipe jacking machines appeared, which began to form the modern seamless steel pipe industry. In the 1930s due to the adoption of a three-roll mill.
Extruders and periodic cold rolling mills improve the variety and quality of steel pipes. In the 1960s, due to the improvement of continuous rolling mills, the emergence of three-roll piercing machines, especially the success of the application of tension reducers and continuous casting billets, improved production efficiency and enhanced the ability of seamless pipes to compete with welded pipes.
In the 1970s, seamless pipes and welded pipes were keeping pace, and the world's steel pipe production was increasing at a rate of more than 5% per year. After 1953, China attached great importance to the development of seamless steel pipe industry, and has initially formed a production system for rolling various large, medium and small pipes.