Seamless steel pipes with small outer diameters can be called small-diameter seamless steel pipes. Small-diameter seamless steel pipes can also be divided into: seamless small-diameter steel pipes and straight seam (also called welded) small-diameter seamless steel pipes, but many people don’t know much about it. How about small-diameter seamless steel pipes? What are the specifications of small-diameter seamless steel pipes? The following Jiuzheng Pipe Network will explain it to you, let’s take a look together.
How about small-diameter seamless steel pipes?
The original state of steel, that is, the delivery state of steel pipes, can be divided into (codes in brackets): cold processing/hard (BK), cold processing/soft (BKW), stress relief annealing after cold processing (BKS), tempering (GBK), normalizing (NBK). The commonly used state is the annealing state, which is convenient for subsequent processing.
The properties and general applications of steel pipes in various states are as follows:
Cold-processed/hard (BK) steel pipes are produced by cold processing of finished products with normal or maximum deformation, without heat treatment, and have the highest dimensional accuracy, highest tensile strength, and lowest elongation coefficient. Generally used to manufacture motorcycle parts, such as shock absorber slides.
Cold-processed/soft (BKW) steel pipes are produced by cold processing of finished products with smaller deformation, without heat treatment, and have the highest dimensional accuracy, high tensile strength, and a certain elongation coefficient (10-15%). Generally used to manufacture automotive parts.
Cold-processed stress-relief annealing (BKS) steel pipes are subjected to low-temperature, rapid heat treatment after cold processing, and have high dimensional accuracy, slightly higher tensile strength, and a certain elongation coefficient (more than 15%). Generally used to manufacture various mechanical parts.
Annealed (GBK) steel pipes are subjected to normal and complete heat treatment after cold processing, and have normal dimensional accuracy, normal tensile strength, and elongation coefficient (more than 20%). It is the most commonly used state and has the widest range of applications.
Normalizing (NBK) is to carry out controlled cooling after complete heat treatment after cold working, with normal dimensional accuracy and slightly higher tensile strength and elongation coefficient (more than 20%). Oil well pipes are in this state.
In addition, the price of steel pipes in steel pipe factories is not closely related to the delivery status, but mainly depends on the specifications, accuracy and length requirements.
Specifications of small-diameter seamless steel pipes:
The specifications of seamless steel pipes are usually expressed by outer diameter * wall thickness (unit: mm). Seamless steel pipes can be divided into two categories according to the production method: hot-rolled seamless steel pipes and cold-rolled (drawn) seamless steel pipes. Hot-rolled seamless steel pipes are divided into general steel pipes, low- and medium-pressure boiler steel pipes, high-pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, geological steel pipes and other steel pipes. In addition to general steel pipes, low- and medium-pressure boiler steel pipes, high-pressure boiler steel pipes, alloy steel pipes, stainless steel pipes, petroleum cracking pipes, and other steel pipes, cold-rolled (drawn) seamless steel pipes also include precision steel pipes, carbon thin-walled steel pipes, alloy thin-walled steel pipes, stainless steel thin-walled steel pipes, special-shaped steel pipes, etc. The outer diameter of hot-rolled seamless pipe is generally greater than 32mm, with a wall thickness of 2.5-75mm. The outer diameter of cold-rolled seamless steel pipe can reach 6mm, with a wall thickness of 0.25mm. The outer diameter of thin-walled pipe can reach 5mm and the wall thickness is less than 0.25mm. Cold rolling has higher dimensional accuracy than hot rolling. In pipeline engineering, when the pipe diameter exceeds 57mm, hot-rolled pipe is often used, and when the pipe diameter is less than 57mm, cold-drawn (rolled) pipe is often used.
The above is an explanation of how small-diameter seamless steel pipes are and what specifications they have. The content is for your reference only. I hope it will help you understand this type of pipe.
https://www.baowi-steel.com