GB crane rail production and use technology covers multiple links such as production and manufacturing and use and maintenance.
Steelmaking
Raw material selection: Use high-quality carbon steel or low-alloy steel as raw material to ensure the purity of molten steel, strictly control the content of harmful elements such as sulfur and phosphorus, so as to ensure the strength, toughness and wear resistance of the rail.
Smelting process: Usually use converter or electric furnace to make steel, and carry out refining operation by accurately controlling parameters such as smelting temperature, time and slag composition, remove impurities and gases in molten steel, and adjust the chemical composition of molten steel to meet the requirements specified in GB standards.
Rolling
Heating: Heat the steel billet obtained by steelmaking to a suitable rolling temperature range, generally 1100-1200℃, so that the steel billet has good plasticity and is easy to roll and deform.
Rolling process: Use multi-pass rolling process, through different stages such as rough rolling, intermediate rolling and finishing rolling, gradually roll the steel billet into the required rail shape and size. During the rolling process, parameters such as rolling speed, reduction and tension are strictly controlled to ensure the dimensional accuracy and internal uniformity of the rails. At the same time, advanced rolling mill equipment and rolling technology, such as universal rolling and online quenching, are used to improve the quality and performance of the rails.
Cooling: The rolled rails need to be properly cooled to obtain good organizational structure and performance. According to different steel types and usage requirements, cooling methods such as air cooling, water cooling or mist cooling can be used. For some rails that need to improve strength and wear resistance, an online quenching process is also used to quickly cool the rails immediately after rolling, so that the surface of the rails forms a hard and wear-resistant martensitic structure while maintaining the toughness of the core.
Finishing
Straightening: Since the rails may bend and twist during the rolling process, the rails need to be straightened by straightening equipment to meet the specified straightness requirements. The straightening process usually adopts methods such as pressure straightening or tensile straightening, which applies a certain external force to the rails to cause plastic deformation, thereby eliminating bending and twisting.
Flaw detection: Use non-destructive testing technologies such as ultrasonic flaw detection and magnetic particle flaw detection to conduct comprehensive flaw detection inspections on the rails to detect whether there are defects such as cracks, pores, inclusions, etc. inside and on the surface of the rails. For defects found, they should be marked and processed in time to ensure the quality and safety of the rails.
Cutting to size: Cut the rails into specified lengths according to user needs. During the cutting process, the flatness and verticality of the cut should be ensured to avoid defects such as burrs and bevels.
Surface treatment: Clean and treat the surface of the rails to remove impurities such as oxide scale and oil stains to improve the surface finish of the rails. If necessary, the rails will also be treated with anti-corrosion treatment, such as spraying anti-rust paint or galvanizing, to extend the service life of the rails.