Alloy steel pipes are widely used as pipes for the machinery industry (mainly hydraulic and pneumatic cylinder pipes, hydraulic oil pipes, automobile transmission shaft pipes and half-shaft sleeves, bearing steel pipes, belt conveyor roller pipes, printing and dyeing roller pipes, etc.), petroleum Geological industrial pipes (oil pump pipes, drilling pipes, oil pipes, casing pipes, drill pipes, etc.), chemical pipes (petroleum cracking pipes, high-pressure pipes for fertilizers, chemical equipment and pipelines), power station boilers and heat exchanger pipes, etc. .