Q345R is a low-alloy high-strength pressure vessel steel under China's GB/T 713 standard, known for its excellent mechanical properties and durability. Its main features include high yield strength (minimum 345 MPa), good toughness and welding performance, as well as stability and corrosion resistance in medium temperature environments (below 450°C). Compared with Q245R, Q345R has higher strength and is suitable for scenes with higher pressures and loads. At the same time, it maintains a low carbon equivalent, which is easy to process and form, and is the preferred material in pressure vessel manufacturing.
The chemical composition of Q345R is reasonably designed, mainly including carbon (C≤0.20%), silicon (Si≤0.55%), manganese (Mn 0.20-1.60%), phosphorus (P≤0.025%), sulfur (S≤0.015%), and may contain trace amounts of chromium (Cr), nickel (Ni) and other elements. Low sulfur and phosphorus content ensures the purity and low-temperature toughness of the steel, while the addition of manganese significantly improves the strength and wear resistance, making it stable under various working conditions.
In terms of size specifications, Q345R can be made into steel plates, steel coils or profiles. The thickness of the steel plate usually ranges from 6 mm to 200 mm, the width is 1500 mm to 4000 mm, and the length can reach 3000 mm to 27000 mm. The specific size can be customized on demand to meet the manufacturing needs of different equipment. The delivery state is generally hot-rolled or normalized. Normalizing treatment can refine the grains and improve the impact resistance and uniformity of the steel. The surface can be sandblasted, galvanized or anti-corrosion coated to enhance durability.
Q345R has a wide range of applications, covering petrochemical, natural gas, electric power and coal chemical industries. It is often used to manufacture high-pressure boilers, gas storage tanks, heat exchangers, reactors and liquefied petroleum gas cylinders and other equipment. It also plays an important role in nuclear power plant pressure vessels, steam generators and industrial pipelines. With its high strength and pressure resistance, Q345R is particularly suitable for engineering projects that need to withstand large stresses and medium temperature environments, becoming a key material in modern industry that combines performance and economy.
