一、钢管在国民经济中的地位凡是两端开口,具有中空断面,而且长度与周长之比较大的钢材,都可以称为钢管。钢管由于有封闭的空心断面,重量较轻,但是却具有较大的抗弯曲和抗扭转强度等优越性能,因而它在国民经济中的应用范围极为广泛。钢管不仅是各种液体和气体良好的输送管道,而且可以取代一部 First, the status of steel pipe in the national economy Any ends open, with a hollow section, and the length and perimeter of the larger steel, can be called steel. Due to its closed hollow section and light weight, the steel pipe has a great performance of resistance to bending and torsional strength. Therefore, it has a wide range of applications in the national economy. Steel pipe is not only a good variety of liquid and gas pipeline, but can replace one