Advantages of ms seamless pipe
MS seamless pipe is a low carbon steel pipe. Low carbon steel pipes are carbon steel pipes with a carbon content of less than 0.25%. Since low carbon steel has low carbon content and good weldability, special process measures are usually not required to obtain high-quality welded joints. Seamless steel pipes, alloy pipes, low and medium pressure boiler pipes, and oil pipes are mostly low carbon steel pipes.
Advantages of ms seamless pipes
1. Cheap and easy to smelt
2. Good processing technology
3. Improve performance (C%, heat treatment)
Disadvantages of ms seamless pipes
Welding characteristics of ms seamless pipe
1. Poor hardenability
2. Low strength level and low yield-to-strength ratio
3. Poor tempering stability and poor heat resistance
Low carbon steel pipes have low carbon and other alloying elements and good plasticity and toughness. Welding generally does not require special process measures such as preheating and post-weld heat treatment, nor does it require complex special equipment. There are no special requirements for the welding power source. Generally, AC and DC arc welding machines can be used for welding. In actual production, due to the good weldability of low carbon steel, almost all welding methods can be selected according to the different processing requirements of the workpiece, and the good quality of the welded joints can be guaranteed.
Heat treatment of ms seamless pipes
The annealed structure of low carbon steel pipe is ferrite and a small amount of pearlite, its strength and hardness are low, and its plasticity and toughness are good. Therefore, it has good cold formability and can be cold formed by curling, bending, stamping and other methods. However, low carbon steel pipes with extremely low carbon content have low hardness and poor cutting processability. Normalizing treatment can improve its cutting processability.
MS seamless pipes have a greater aging tendency, including both quenching and aging tendencies. When steel is rapidly cooled from high temperatures, the carbon and nitrogen in the ferrite are in a supersaturated state and can slowly form iron carbonitride at room temperature. Therefore, the strength and hardness of the steel increase, while the plasticity and ductility are improved. Decreased toughness. This phenomenon is called quenching aging. Low carbon steel pipes will age even if they are not quenched or air-cooled. A large number of dislocations are generated after deformation. The carbon and nitrogen atoms in the ferrite interact elastically with the dislocations, and the carbon and nitrogen atoms gather around the dislocation lines. This combination of carbon and nitrogen atoms and dislocation lines is called an old Coriolis air mass (Korpal air mass). It increases the strength and hardness of steel while reducing its plasticity and toughness, a phenomenon called deformation aging.
Mild steel pipes are sometimes limited in their use due to their lower strength. Appropriately increasing the manganese content in carbon steel and adding trace amounts of vanadium, titanium, niobium and other alloying elements can greatly improve the strength of steel pipes. If the carbon content in the steel is reduced and a small amount of aluminum, a small amount of boron and carbide forming elements are added, an ultra-low carbon bainite group with high strength, good plasticity and toughness can be obtained.
Although low carbon steel pipes are the most weldable steel pipes, welding defects such as pores, inclusions, and cracks will inevitably occur during the welding process. Therefore, corresponding measures should be taken when welding low carbon steel pipes to ensure the quality of the weld.