Types of seamless carbon steel pipes
The various types of seamless carbon steel pipes available today can be divided into three main categories: Hot rolled seamless steel pipe (hrs), cold rolled seamless steel pipe (crs) and cold drawn seamless steel pipe (cds). Within each category there are several variants dedicated to specific applications (such as oil or gas transportation) or certain intensities.
Hot rolled seamless tube
The hot-rolled seamless pipe is made from a heated round billet and formed into a cylindrical shape. They are often used in engineering applications requiring higher strength than cold rolled or cds tubes. The heat treatment process makes them extra hard and strong, able to withstand high temperatures and pressures. Advantages of hot-rolled seamless tubes include cost-effectiveness, strong construction, and the ability to customize shapes. Drawbacks include their weight, which can make them difficult to transport and install. Hot rolled seamless pipe is often used for larger projects involving higher pressures and temperatures.
Cold rolled seamless tube
Cold-rolled seamless pipe is made by shaping hot-rolled steel through a series of rolls. Unlike hot rolled steel, cold rolled steel is harder and more brittle. It also allows for more precise machining and shaping, making it ideal for equipment that requires precision. The advantages of cold-rolled tubes include greater resistance to corrosion and wear, better machinability, and lower cost. Disadvantages of cold-rolled pipe include insufficient strength compared to hot-rolled steel, a greater likelihood of cracking, and limited customizability. Cold-rolled tubing is often used in smaller applications that don't require as much strength or precision.
Cold drawn seamless tube
Cold-drawn seamless tubes are made by forcing hot-rolled tubes through one or more dies. This forces the material to become denser, making it stronger. They are ideal for applications where strength and pressure resistance are critical, such as automotive hydraulic lines and tubing. Advantages of cold-drawn seamless tubing include high strength, low cost, and the ability to manufacture precise shapes. Drawbacks include their potential to crack if not properly tempered, lack of flexibility, and limited customizability. Cold drawn seamless tubing is most commonly used in automotive and industrial applications.
General seamless carbon steel pipe: It is made by hot rolling or cold rolling of high-quality carbon steel such as 10, 20, 30, 35, 45, 16mn, 5mnv and other low alloy structural steel or 40cr, 30crmnsi, 45mn2, 40mnb and other alloy steel. 10, 20 and other low carbon steel seamless pipes are mainly used for fluid conveying pipelines. Seamless tubes made of medium carbon steel such as 45 and 40cr are used to manufacture mechanical parts, such as stressed parts of automobiles and tractors. Generally, seamless steel pipes are used to ensure strength and flattening tests. Hot-rolled steel pipes are delivered in a hot-rolled or heat-treated state; cold-rolled steel pipes are delivered in a heat-treated state.
Seamless steel pipes for low and medium pressure boilers: Used to manufacture various low and medium pressure boilers, superheated steam pipes, boiling water pipes, water wall pipes and superheated steam pipes for locomotive boilers, large smoke pipes, small smoke pipes and arch brick pipes, etc. Hot-rolled or cold-rolled (dial) seamless steel pipes are made of high-quality carbon structural steel. It is mainly made of no. 10 and no. 20 steel. In addition to ensuring the chemical composition and mechanical properties, hydrostatic tests, crimping, flaring, and flattening tests are required. Hot rolling is delivered in a hot rolled state, and cold rolling (dial) is delivered in a heat treated state.
High-pressure boiler steel pipe: Mainly used to manufacture high-quality carbon structural steel, alloy structural steel and stainless heat-resistant steel seamless steel pipe for steam boiler pipes with high pressure and above pressure. These boiler pipes often work under high temperature and high pressure. The pipe will also be oxidized and corroded under the action of high-temperature flue gas and water vapor. Therefore, the steel pipe is required to have high durable strength, high oxidation resistance, and good structural stability.
