Method for preventing flocculation flow of small square billet medium-carbon high-silicon low-manganese steel

Abstract

The invention provides a method for preventing the flocculation flow of small square billet medium-carbon high-silicon low-manganese steel. Compared with the prior art, the method has the advantages that in order to improve the castability of the medium-carbon high-silicon steel, an end-point oxygen content and early-stage rapid slagging are controlled by optimizing end-point carbon and slag charge ratio of converter tapping, in a LF furnace process, large slag amount and high alkalinity are adopted to facilitate the deoxidation and desulfurization process, then a ladle argon blowing process is reasonably controlled, the argon blowing strength is properly set, the argon blowing time is properly prolonged, the floating and removal of oxide, sulfide and other inclusions in steel can be promoted, and the continuous casting nodulation can be obviously reduced through measures such as continuous casting process protection casting. Meanwhile, the molten steel casting temperature is properlyincreased, and the flocculation flow blockage phenomenon of a continuous casting intrusive water nozzle can be effectively avoided. By means of the method, the flocculation flow phenomenon of a smallsquare billet in the medium-carbon high-silicon steel PSB830 pouring process is reduced, and the multi-furnace stable continuous pouring and batch production are achieved.

Description

technical field [0001] The invention belongs to the field of steel smelting, and in particular relates to a method for preventing flocculation of carbon-high-silicon-low-manganese steel in a billet. Background technique [0002] Medium-carbon high-silicon low-manganese steel PSB830 is rolled into a straight steel bar with high strength and high dimensional accuracy. The steel bar requires a connector or anchor with an internal thread to be connected or anchored at any cross-section. It is widely used in large water conservancy projects, continuous beams and large frame structures in industrial and civil buildings, large and medium-span bridges in highways and railways, nuclear power plants and ground anchors and other projects. It has the advantages of simple connection and anchoring, strong adhesion, safe and reliable tension anchoring, and convenient construction, and it saves steel bars and reduces the area and weight of components. The construction of infrastructure suc...

AI Technical Summary

Problems solved by technology

[0003] However, because the composition design of PSB830 steel belongs to medium-carbon high-silicon and low-manganese steel, the Mn / Si of the steel itself is relatively low, about 0.6, and the castability is poor. The melting point inclusions adhere to the inner wall of the nozzle, aggravating the occurrence of nozzle flocculation blocking the nozzle, and then causing the fluctuation of the liquid steel level in the crystallizer, and even burning oxygen to maintain the pouring, which will inevitably pollute the molten steel and affect the quality of the billet. Forcing the downgrading or scrapping of abnormal billets in the process

When the nozzle is seriously blocked, it may even cause the casting machine to stop pouring

Therefore, the flocculation problem at the tundish nozzle is a major obstacle to the realization of high-efficiency continuous casting of medium-carbon high-silicon and low-manganese steel

Images