，主题：Hot Rolled Flat Steel (GB/T704-1988)
Hot rolled flat steel is a very popular steel product in the steel industry. It has been used for centuries for a variety of applications, mainly due to its mechanical properties, durability, strength and overall affordability. It is produced in two forms, known as flat products and bar products. Flat products are typically used in many construction and manufacturing applications, while bar products are mainly used in engineering, fabrication and machining applications.
Hot rolled flat steel is produced by rolling steel through a set of rollers. This process creates a uniform, flat product with the thickness of the product determined by the size of the rollers and the speed of the rollers. It is generally produced in sizes between 2mm to 400mm width. Once finished, the product can be cut and prepared for further processing or direct-use applications such as in sheet metal work, automotive components and structural components.
Hot rolled flat steel can be divided into two types, hot-rolled and cold-rolled. Hot-rolled flat steel is produced by heating the metal above its recrystalization temperature, followed by rolling it through a set of rollers to bring it to its desired size and shape. The metal is then allowed to cool down, and the process is then repeated for the next product. Cold-rolled flat steel is produced in a similar fashion, except that the final product is usually much more precise in size and shape due to the cooling of the metal being slower and more uniform than hot-rolled.
In China, hot rolled flat steel is specified by the GB/T704-1988 Standard by the Chinese National Standards Committee. This standard defines the quality characteristics of hot rolled flat steel, including its chemical composition, mechanical properties and tolerances. Moreover, it provides with the requirements and test methods for non-destructive testing and other related specifications.
The typical chemical composition of hot rolled flat steel includes carbon, manganese, phosphorus, sulfur, nitrogen and aluminum. It is also necessary to meet certain strength requirements such as tensile strength, yield strength and percent elongation. Furthermore, the surface defects of the flat steel must meet the specified limits.
In addition to the traditional uses of hot rolled flat steel, it also beneficial for many new and modern applications such as in the automotive and aerospace industries. It is becoming more common for these industries to utilize hot rolled flat steel due to its superior mechanical and physical properties and overall affordability.
Overall, hot rolled flat steel is a very popular and versatile product for many different industries, due to its mechanical properties, durability, strength and overall affordability. It can be easily produced in various sizes and shapes and also meets the requirements of many international standards, such as the GB/T704-1988 Standard in China. The uses of this product are also increasing due to its use in many new and modern applications, such as in the automotive and aerospace industries.
