Tensile strength of seamless steel pipe

Seamless steel pipes are commonly used as raw materials for ring-shaped metal parts. This approach streamlines production by eliminating many complex processes, significantly reducing wear and tear on stainless steel plates, and saving on product costs. The basic production principle is straightforward and can be compared to slicing kale with a knife to quickly create ring-shaped parts with minimal wear.

However, seamless steel pipes with annular cross-sections have their limitations. Their bending strength is relatively low, making them unsuitable for bearing heavy loads. Consequently, in applications such as agricultural machinery frames and furniture, these pipes are often forged into square or rectangular shapes to enhance their tensile strength.

Typically, seamless steel pipes refer to those with diameters of 402 mm or more, encompassing both thick-walled seamless steel pipes and thick-walled seamless pipes. The production technology for large-diameter seamless steel pipes involves hot rolling. Compared to the original large-diameter hot-rolled pipes, hot-expanded seamless steel pipes are more cost-effective, although their production cycle is longer. This cost efficiency has led manufacturers to reduce the production of original hot-rolled seamless pipes. In terms of quality, hot-expanded seamless steel pipes do not match the original hot-rolled pipes.

After hot rolling or forging, seamless steel pipes made from stainless steel sheets do not undergo professional heat treatment and are delivered immediately after cooling, a process known as hot rolling or hot forging. The stopping temperature for hot rolling or forging is generally between 800°C and 900°C, after which the material is typically air-cooled, making the hot rolling or forging process akin to quenching. In contrast, seamless steel pipe stainless steel plates are quenched and heat-treated before leaving the factory, a delivery condition referred to as the quenching situation.