Smelting method for stably controlling temperature of heavy rail steel U75V tundish

Abstract

The invention discloses a smelting method for stably controlling the temperature of a heavy rail steel U75V tundish. The smelting method comprises the processes of pre-desulfuration for molten iron, smelting in a rotating furnace, LF refining, RH refining and continuous casting. According to the smelting method, under the condition of not increasing the production cost, the viscosity of refining slag of a steel ladle is controlled to achieve a good heat preservation effect, the temperature change of the tundish is lower than 10 DEG C in the casting process, so that the superheat degree of themolten iron of the tundish is controlled within a change section of 20-30 DEG C, the loose center and shrinkage cavity defects of a casting blank are obviously overcome, the macroscopic defects such as center cracks, middle cracks and corner cracks of the casting blank are effectively prevented, and the demand for a heavy rail steel at present is met; the qualification rate of the temperature of the molten iron of the tundish produced for the heavy rail steel is greater than or equal to 95%, so that the degradation judgement change rate of temperature ultralimit is lowered by 90% or above, macroscopic examination for the steel rail is qualified, the flaw detection qualification rate is 98-99.5%, low-superheat-degree casting is achieved, the quality stability and qualification rate of products are improved, and the smelting method has a wide application prospect.

Description

technical field

[0001] The invention belongs to the technical field of metallurgy, and in particular relates to a smelting method for stably controlling the temperature of a heavy rail steel U75V tundish. Background technique

[0002] Heavy rail steel is the main component of railway tracks. With the rapid development of my country's high-speed railways and the speed-up of heavy-rail railways, the demand for high-speed steel rails is increasing. There are 19,000 kilometers of railways, but it is still difficult to meet the huge transportation demand. According to the 2016 version of the "Medium and Long-Term Railway Network Plan" released by the Ministry of Railways, by 2020, a number of major landmark projects will be completed and put into operation, and the scale of the railway network will reach 150,000 kilometers, including 30,000 kilometers of high-speed railways, covering more than 80% of large cities .

[0003] In the process of railway transportation, the rails pro...

Images