它们通常适用冷拔无缝钢管的材质，冷拔无缝钢管又分为GB8162、GB8163这两个常用的，但45#钢只有GB8162才有，45#是机械加工的一种常用材质。首先来说20#和45#钢的c、Si、Mn、P、S含量不同，45要高于20#钢，你可以买本钢材只是手册看一下。20#钢淬透性、淬硬性低、塑性、韧性、焊接性好，热轧或正火后韧性更好，可制作不太重要的中、小型渗碳、碳氮共渗件、锻压件，如杠杆轴、变速箱变速叉、齿轮，重型机械拉杆、钩环等。45#钢是常用中碳调质钢，综合力学性能良好，淬透性低，水淬时易生裂纹。小型件宜采用调质处理，大型件宜采用正火处理，主要用于制造强度高的运动件，如透平机叶轮、压缩机活塞。轴、齿轮、齿条、蜗杆等。

They are usually suitable for cold-drawn seamless steel pipes. Cold-drawn seamless steel pipes are divided into GB8162 and GB8163, which are commonly used. But 45# steel only has GB8162, and 45# is a common material for mechanical processing. First of all, the contents of C, Si, Mn, P and S of 20 # and 45 # steel are different. 45 is higher than 20 # steel. You can buy this steel just for a brochure. 20 # steel has low hardenability, low hardenability, good plasticity, toughness and weldability. It has better toughness after hot rolling or normalizing. It can be used to make small and medium-sized carburizing, carbonitriding and forging parts, such as lever shaft, transmission fork, gear, heavy mechanical tie rod, hook ring, etc. 45# steel is commonly used medium carbon quenched and tempered steel. It has good comprehensive mechanical properties, low hardenability and easy to crack when quenched by water. Small parts should be tempered, large parts should be normalized, mainly for the manufacture of high intensity moving parts, such as turbine impeller, compressor piston. Shaft, gear, rack, worm, etc.

它们通常适用冷拔无缝钢管的材质，冷拔无缝钢管又分为GB8162、GB8163这两个常用的，但45#钢只有GB8162才有，45#是机械加工的一种常用钢管材质。

They are usually suitable for cold-drawn seamless steel pipes. Cold-drawn seamless steel pipes are divided into GB8162 and GB8163, which are commonly used. But 45# steel only has GB8162, and 45# is a commonly used steel pipe material for mechanical processing. 普通冷拔冷拔无缝钢管与精轧冷拔无缝钢管的区别在于

The difference between ordinary cold-drawn seamless steel tube and finishing cold-drawn seamless steel tube is that

1、普通冷拔无缝钢管主要特点是无焊接缝，可承受较大的压力。产品可以是很粗糙的铸态或冷拨件，适合用于机械加工，流体管道。

1. The main characteristic of common cold-drawn seamless steel pipe is that it has no welding seam and can withstand large pressure. Products can be very rough as-cast or cold-dial parts, suitable for mechanical processing, fluid pipelines.

2、精密钢管是近几年出现的产品，主要是内孔、外壁尺寸有严格的公差及粗糙度，外表光亮，但唯一的一个缺点是不可以握弯，解决方法最后退火但是退火后就不会发光了但是壁厚公差还可以保证。

2. Precision steel pipe is a product that has appeared in recent years. It has strict tolerance and roughness for inner hole and outer wall, and its appearance is bright. But the only disadvantage is that it can't hold bend. The solution is annealed at last, but it won't glow after annealing, but the wall thickness tolerance can also be guaranteed.