Posted 28 Dec 2010 22:05
Amount of nitrogen content in steel can with Nb, V, Ti, Al and other elements combined grain refinement and solid solution strengthening to improve the strength of steel, but with the free nitrogen content in steel increased, showing the steel toughness, weldability, reduce heat stress zone toughness, fragility, resulting in slab cracking, high-line time significantly, folded twisted wire breakage problems. General requirements for high-carbon steel products, high strength, good toughness, nitrogen content in steel requirements lower. Nitrogen content of the steel converter to 15 10-6, compared with the converter, electric furnace smelting hot metal do not have the high ratio of large oxygen intensity, high decarburization rate, and nitrogen uptake in the arc area is easy, effective as nitrogen converter Even loaded to the furnace hot metal above 80%, but far less oxygen intensity decarbonization rate converter, the Steel 100t EAF-LF-casting (billet, slab) production processes and micro-alloy high strength high carbon billet slab steel production practice, the control of nitrogen content of the relevant technology. A large number of practical results the following conclusions: The furnace carbon content and a substantial increase with the oxygen, oxygen lance smelting process by oxygen blowing control technology cluster, ensure that the carbon content of steel to reduce carbon agent usage, depending on the steel oxygen species in different ways, to reduce the absorption of nitrogen steel; refining furnace control the slag foaming, reduce the occurrence of secondary contact with air oxidation; casting stable operation, good control of argon closure, the package temperature, nitrogen content of the slab to stabilize control in normal levels, is now stable product of nitrogen content in kind, silicon killed steel billet SWRH82B species in 48 10-6 ~ 55 10-6, varieties of Al-killed steel slab AH32/AH36 nitrogen content in the 65 10 -6 ~ 70 10-6.