ASTM A106 Cold drawn or Hot rolled seamless steel pipe: Which one is better?

　　As the two main production processes of ASTM A106 seamless steel pipes (SMLS), cold drawing and hot rolling each have their own unique advantages and disadvantages and are suitable for different occasions. The following is a detailed analysis of the advantages and disadvantages of cold drawing and hot rolling of seamless steel pipes and their applicable occasions:

　　Differences in manufacturing processes:

　　ASTM A106 Cold drawn seamless pipe: Made through multiple drawing and annealing treatments, using high carbon steel or alloy steel, with high strength, hardness and fatigue resistance, but relatively poor toughness. It has high outer diameter accuracy and uniform wall thickness, and is suitable for high-precision, high-pressure, high-temperature and special medium transportation occasions.

　　ASTM A106 Hot rolled seamless pipe: Made through a rolling process at high temperature, using low carbon steel or low alloy steel, with low strength and hardness, but good toughness, easy to process and weld. It has a larger outer diameter and a rougher surface, suitable for structural parts and fluid delivery pipelines that do not require high strength but require good toughness.

　　Advantages and disadvantages of ASTM A106 cold-drawn seamless steel pipes:

　　Advantages:

　　1. High dimensional accuracy: Cold-drawn seamless steel pipes are rolled at room temperature, so their dimensional accuracy is high, the wall thickness is uniform, and the deviation of the pipe diameter and wall thickness is small. This makes cold-drawn seamless steel pipes have significant advantages in situations where high-precision dimensions are required.

　　2. Good surface finish: The cold drawing process can make the surface of the steel pipe smoother, reduce surface roughness and burrs, thereby improving the aesthetics and corrosion resistance of the product.

　　3. Good mechanical properties: Cold-drawn seamless steel pipes have high tensile strength and yield point, which can meet the requirements of high strength and hardness.

　　Disadvantages:

　　1. Residual stress: During the cold rolling process, residual stress may be generated inside the steel pipe, which may have a certain impact on the overall and local performance of the steel pipe.

　　2. Poor torsional performance: The style of cold-rolled steel sections is generally an open section, which makes the free torsional stiffness of the section low and the torsional performance relatively poor.

　　3. High cost: Since the cold rolling process is relatively complex and has high requirements for equipment, the production cost of cold-rolled seamless steel pipes is relatively high.

　　Applicable occasions for ASTM A106 cold-drawn seamless steel pipes:

　　a. Occasions with high precision requirements: such as precision machinery, hydraulic equipment and other fields, high-precision and high-finish seamless steel pipes are required.

　　b. Occasions with high corrosion resistance requirements: such as chemical, petroleum and other industries, the surface finish of cold-drawn seamless steel pipes helps to improve their corrosion resistance.

　　c. Occasions with high requirements for mechanical properties: such as aerospace, automobile manufacturing and other fields, high-strength and hardness seamless steel pipes are required.

　　Advantages and disadvantages of ASTM A106 hot-rolled seamless steel pipes:

　　Advantages:

　　1. Simple process: Hot-rolled seamless steel pipes are rolled after high-temperature heating, the process is relatively simple, and the production efficiency is high.

　　2. Low cost: Since the hot rolling process is relatively simple and the equipment requirements are relatively low, the production cost of hot-rolled seamless steel pipes is low.

　　3. Good toughness: The impact toughness of hot-rolled seamless steel pipes is good, and they can adapt to some occasions that need to withstand impact loads.

　　Disadvantages:

　　1. Low dimensional accuracy: Due to the phenomenon of thermal expansion and contraction during hot rolling, the dimensional accuracy of hot-rolled seamless steel pipes is relatively low.

　　2. Poor surface quality: The surface of hot-rolled seamless steel pipes may have defects such as scale and red rust, which require subsequent treatment.

　　3. Relatively poor mechanical properties: Compared with cold-rolled seamless steel pipes, the tensile strength and yield point of hot-rolled seamless steel pipes are relatively low.

　　Applicable occasions for ASTM A106 hot-rolled seamless steel pipes:

　　a. Occasions with low requirements for dimensional accuracy: such as construction, general machinery manufacturing and other fields, the dimensional accuracy requirements for seamless steel pipes are not high.

　　b. Mass production occasions: Due to the high production efficiency and low cost of hot rolling process, it is suitable for mass production occasions.

　　c. Occasions that need to withstand impact loads: such as bridges, ships and other fields, seamless steel pipes are required to have a certain impact toughness.

　　ASTM A106 hot-rolled seamless steel pipes or ASTM A106  cold-drawn seamless steel pipes mainly depends on the specific application requirements and scenarios to ensure the quality and benefits of the project.