Optimization And Research On The Production Process Of 65Mn Steel

Since 2015,the production of high quality carbon structural steel in Guofeng company has increased month by month.Based on the typical 65Mn steel,its production in 2015 was 18800 tons,and from January to March in 2016,the production reached 5800 tons.However,with the production growth,the quality problems exposed during the productive process are also increasingly prominent.It is not only has produced more quality objection and the company's quality waste,but also restricted seriously the company's high quality carbon structural steel capaity to develop.The main problems of 65Mn steel include abnormal components,central segregation,slab crack and nozzle clogging,etc.In this paper,By the research and optimization of the 65 Mn process,and conclude the following conclusions.(1)Using the low nitrogen tar carburant to replace the original coal carburant in the operation of the converter carburant.The carburant which has the advantages of fast melting speed and stable carburant quantity can ensure good refining conditions of molten steel.(2)Using the pdofsifer to replace the aluminum powder to slag in the refining process.This can reduce the content of the steel slag Al2O3 and increase the quantity that the refined white slag adsorb the Al2O3.Besides,it can improve the purity of molten steel effectively and reduce the accident of nozzle flocculation.(3)The temperature of the molten steel in tundish casting is controlled at 1515±5?,which can alleviate the casting billets' central segregation and porosity flaws.(4)Stabilize the temperature of the crystallizer's water inlet,optimize the crystallizer's water volume and make it become 1900 L/min,control the temperature rise of the crystallizer's water inlet and outlet at 7.5? eliminate the effect that the season to the temperature of the crystallizer's water inlet and stabilize the cooling strength of the crystallizer.(5)During casting the 65Mn steel,the taper of the crystallizer should be controlled at 1.5-1.6 mm to ensure the effect of its heat transfer.During process of the casting the 65Mn steel,the secondary cooling zone take the weak cooling mode and make the specific water flow of the secondary cooling zone 0.52-0.544 L/t,and this can reduce the degree of the longitudinal cracking on casting billets.