What are the differences between cold-drawn steel pipes and hot-rolled steel pipes

The difference between hot and cold working: Hot rolling is hot working, while cold drawing is cold working. The main difference is that hot rolling is performed above the recrystallization temperature, while cold rolling is performed below the recrystallization temperature. Cold rolling sometimes involves heating, but at a lower temperature, because it produces work hardening. If high forming requirements are needed, annealing is also required.

Cold-rolled and hot-rolled steel are generally plates or profiles, while cold-drawn steel is generally wire with a cylindrical cross-section. Additionally, hot-rolled plates are generally high-alloy, high-strength steel, while cold-rolled steel is low-carbon, low-alloy steel. Cold rolling increases strength and ensures surface quality.

The difference between cold-drawn seamless steel pipes and hot-rolled seamless steel pipes is different from that of plates.

Seamless steel pipes are divided into hot-rolled (extruded) seamless steel pipes and cold-drawn (rolled) seamless steel pipes due to their different manufacturing processes.

Cold-drawn steel pipes typically require multiple drawing processes, with stress-relieving annealing between each drawing to ensure smooth operation in the next cold drawing. Visually, cold-rolled seamless steel pipes are often smaller in diameter, while hot-rolled seamless steel pipes are often larger. Cold-rolled seamless steel pipes have higher precision and are more expensive than hot-rolled seamless steel pipes. Cold-drawn seamless steel pipes generally have smaller diameters, mostly below 127mm, and their outer diameter precision is particularly high. The length of cold-drawn seamless steel pipes is generally shorter than that of hot-rolled seamless steel pipes. In terms of wall thickness, cold-drawn seamless steel pipes are more uniform than hot-rolled seamless steel pipes.