PROCESS OPTIMIZATION FOR IMPROVING CONVERTER ENDPOINT HIT RATE OF LOW-CARBON STEEL
In response to the problems of severe slag overflow in the early stage of decarbonization,low endpoint hit rate,and high consumption of slag forming materials during the production of low-carbon steel in a 90 ton converter in a domestic factory,the oxygen lance nozzle of the converter,the position of the oxygen lance in the early stage of decarbonization,the carbon pulling time in the late stage of decarbonization,the amount and method of slag forming materials added,and the bottom blowing process mode were optimized.Firstly,the parameters of the oxygen lance nozzle in the converter were adjusted to achieve better stirring effect.At the same time,adjust the position of the oxygen gun in the early stage and advance the slag pressing time by 0.5 minutes to avoid slag overflow.Secondly,reduce the amount of slag material added,calculate its alkalinity and sulfur phosphorus ratio based on the endpoint slag composition of the original process,determine the appropriate alkalinity,and calculate the amount of lime added.Finally,the bottom blowing flow rate was increased from 0.027 m3/(t·min)to 0.069 m3/(t·min),and the carbon pulling time of the pressure gun in the later stage of blowing was extended by 10～15 seconds to improve the accuracy of the endpoint carbon content.The industrial test results show that the new process increases the endpoint temperature hit rate(t ≥ 1 630 ℃)by 8.96％,endpoint carbon content hit rate(％C 0.06％)by 24.91％,endpoint phosphorus(ω(P)≤0.020％)and sulfur hit rates(w(S)≤0.020％)by 8.4％and 17.32％,respectively.The total amount of slag materials(limestone and lime)decreased by 4.88 kg/t of steel.At the same time,the smelting time was shortened by 0.5 minutes,which improved production efficiency.
converterlow carbon steelendpoint hit rateoxygen lance positionslag forming material
万方数据
维普
