Hot-Rolled Steel Bars
Hot-rolled steel bars are metal bars that are hot-processed from raw steel material, which is cooled and then processed through heat-treatments, depending on the grade and application of the metal bar. Hot-rolled steel bars are produced at temperatures higher than 1900°F (1038°C), which shapes and forms the metal bar. Hot-rolled steel bars can be used in a variety of applications; most commonly, they are seen in construction, shipbuilding and automotive industries.
Hot-rolled steel bars come in various shapes, sizes, and grades. Grades are determined by the metals carbon and alloy content. Common grades of hot-rolled steel bars include: low and medium carbon steels; low and medium alloy steels; stainless steels; nickel alloys; and certain aluminum alloys. Common shapes of hot-rolled steel bars include rounds, flats, and squares, which are all available in varying sizes.
The size and shape of a hot-rolled steel bar are determined by its specification. This specification is based on the bars dimensions (length, width, and thickness) and the way it is cut. Hot-rolled steel bars can be purchased in either bundled form or as loose bars. The bars can be bundled in sizes of bundles ranging from 10 - 27 tons.
When purchasing a hot-rolled steel bar, there are certain important considerations: the mill tolerance, mechanical properties, and surface quality. Mill tolerance refers to the allowable differences between the specified sizes of a hot-rolled steel bar. Mechanical properties refer to the stress/strain resistance of the material, as well as its hardness, ductility, and impact resistance. Finally, surface quality refers to the surface finish of the bar, specifying the amount of processing such as shot blasting, plating, sandblasting, and polishing.
After hot-rolling, hot-rolled steel bars are cooled and go through post-processing treatments such as quenching and tempering. Heat-treating hot-rolled steel bars can increase the strength, machinability, and corrosion resistance of the bar. The post-processing treatments determine the mechanical properties of the steel bar.
The weight of hot-rolled steel bars is based on its GB 13014-1991 standard. According to this standard, the average weight of hot-rolled steel bars ranges from 545-793kg/m. This standard also specifies the dimensions of a hot-rolled steel bar, ranging from 5-20 millimeters in diameter and 0.3-3 millimeters in thickness. Hot-rolled steel bars with diameters larger than 20 millimeters and thickness greater than 3 millimeters should be specified at the time of purchase.
In conclusion, hot-rolled steel bars are metal bars that are hot-processed from raw steel material, which is cooled and then processed through heat-treatments, depending on the grade and application of the metal bar. Hot-rolled steel bars come in various shapes, sizes, and grades, with their dimensions and weight determined by GB 13014-1991 standard. Heat treatments can increase the strength, machinability, and corrosion resistance of the bar. Hot-rolled steel bars are commonly used in the construction, shipbuilding and automotive industries.
