Hot Rolling Treatment of Mild Steel Tubes

‌Hot-rolled mild steel tube‌ refers to mild steel tubes produced through hot rolling process. The carbon content of mild steel tube is low, usually no more than 0.25%, which makes it less likely to crack during processing, and the strength and toughness of the joint after welding can be guaranteed. The hot rolling process of mild steel tubes is rolling above the recrystallization temperature. The metal has high plasticity and low deformation resistance at high temperatures, which can significantly reduce energy consumption and costs.

Hot rolled mild steel tube has the following performance characteristics:

‌1. Good plasticity and toughness

Due to rolling at high temperatures, steel has better plasticity and toughness, making it suitable for applications that need to withstand greater stress.

‌2. Surface quality is relatively poor

During the hot rolling process, some defects may occur on the surface of the steel, such as oxide scale, scratches, etc., which affect the surface quality.

‌3. High material utilization rate‌

The hot rolling process can make full use of raw materials, reduce material waste, and reduce costs.

The hot rolling treatment of mild steel tubes mainly includes the following steps:

‌1. Raw material preparation‌

The main raw material of mild steel tube is low carbon steel plate. The steel plate first needs to be cut into slabs of appropriate size. Then, the slab needs to undergo rust removal and surface treatment to remove oxides and impurities on the surface to provide good conditions for subsequent processing.

‌2. Steel pipe rolling‌

The tube shape is formed by rolling and drawing the steel slab through multiple passes. The steel slab is heated to an appropriate temperature and rolled through multiple passes to gradually form a tube shape. During the rolling process, the size and wall thickness of the pipe need to be controlled, and the rolls must be maintained and replaced regularly to ensure product quality and production efficiency‌.

3. Welding‌

Welding is the process of joining rolled steel slabs. According to the different welding methods, it can be divided into long welding and spiral welding. Long welding is to weld the two ends of the steel plate to form a long tube; spiral welding is to spirally weld the steel plate around the central axis to form a tube. Choose appropriate welding methods and materials to ensure the quality and strength of the weld‌1.

‌4. Heat treatment‌

Heat treatment is to improve the structure and performance of mild steel tubes. Common heat treatment processes include annealing, normalizing, quenching, etc. Annealing is to heat the steel pipe to an appropriate temperature and then slowly cool it to soften the steel and improve its plasticity and toughness; normalizing is to achieve a certain hardness and strength by controlling the cooling rate; quenching is to heat the steel pipe to an appropriate temperature and then cool it quickly to achieve High hardness and high strength‌.

‌5. Other processing‌

After hot rolling, steps such as pickling, cutting, shaping and surface treatment are also required. Pickling removes oxides and rust on the surface of the steel to improve surface quality; cutting is carried out to the length required by the customer; molding is passed through the forming machine to ensure that the pipe shape meets the regulations; surface treatment such as galvanizing, spraying and plastic plating, etc., improves corrosion resistance‌.

Hot-rolled mild steel tubes are widely used in the market and are mainly used in the following fields:

‌1. Oil and natural gas transportation‌

Hot-rolled steel pipes have good strength and corrosion resistance and are suitable for transporting oil and natural gas.

‌2. Building structure‌

It is used for structural parts such as columns and beams in buildings because of its high strength and low cost.

‌3. Machinery manufacturing‌

In machinery manufacturing, hot-rolled steel pipes are used to manufacture various transmission shafts, cylinders and other components.

‌4. Other industrial applications‌

It is also widely used in chemical industry, electric power and other fields.

Summarize

In summary, the mild steel tube hot rolling process has high production efficiency and material utilization during the production process. The product performance has good plasticity and toughness, but the surface quality is relatively poor. It has a wide range of market applications, mainly used in petroleum, natural gas transportation, building structures, machinery manufacturing and other fields.

Article source: https://article-realm.com/article/Business/69869-Hot-Rolling-Treatment-of-Mild-Steel-Tubes.html