Introduction
GB/T 4171-2000 high-resistance structural steel is a higher corrosion resistance steel compared to ordinary carbon structural steel. Developed primarily for outdoor applications, it is suitable for use in machining, welding and bending parts and components. It is an important structural material for industrial and home use. This article will provide an overview of GB/T 4171-2000 grade designation and its chemical composition.
Overview of GB/T 4171-2000 Grade Designation
GB/T 4171-2000 grade designation is a system which classifies high-resistance structural steel based on their composition. Each grade is assigned a number, with higher numbers indicating higher strength and resistance to corrosion. These numbers follow the format ‘T
The grade designations in GB/T 4171-2000 are split into two categories, ‘No-etch’ and ‘etch’ grades. No-etch grades have a tensile strength of between 590 and 1100MPa and a corrosion class 4 to 12. Etch grades have a tensile strength of between 590 and 1180MPa and a corrosion class 8 to 12.
Chemical Composition
The chemical composition of GB/T 4171-2000 high-resistance structural steel is determined according to its grade designation. The main alloying elements are C, Si, Mn, P, and S, with less significant amounts of other elements such as V, Al, Nb, Mo and Cr. These levels are kept low to ensure that the structure of the steel remains sound, and to prevent cracking and other problems that can occur with the introduction of excess amounts of any one of these elements.
The carbon content of the steel dictates its hardness and strength, and ranges from 0.15% to 1.2%. Manganese is usually the primary alloying element after carbon, and ranges from 0.5% to 1.2%. Silicon, phosphorus and sulphur all have an impact on hardenability, microstructure and machining, and generally range from 0.2% to 0.8%. V, Al, Nb, Mo and Cr will all have small amounts present to improve mechanical and corrosion resistance, but none will exceed 0.2%.
Conclusion
GB/T 4171-2000 high-resistance structural steel is a corrosion-resistant steel developed for outdoor use. It is classified according to their grade designation, with No-etch grades having a tensile strength of between 590 and 1100MPa and a corrosion class 4 to 12, and etch grades having a tensile strength of between 590 and 1180MPa and a corrosion class 8 to 12. Its chemical composition is determined according to its grade designation, with elements such as carbon, silicon, manganese, phosphorus, sulfur, V, Al, Nb, Mo and Cr all having an effect on its properties.
