Rare earth heat-resistant stainless steel continuous casting method

Abstract

The invention discloses a rare earth heat-resistant stainless steel continuous casting method. The method comprises the following steps: selecting alloy steel with preset mass percentage; feeding a pure Ce rare earth line into molten steel in an LF refining furnace, wherein the feeding quantity is determined according to the weight of the molten steel; after feeding the line, performing argon blowing and stirring; sealing a tundish cover and a turndish contact face by refractory clay, sealing all the opening holes in the tundish by a ceramic fiber board and injecting argon to empty the air inthe tundish; performing continuous casting large ladle pouring and controlling the molten steel quantity and the molten steel temperature of the tundish to be within a preset range; and opening a tundish stopper rod mechanism, pouring the molten steel into a crystallizer, starting a continuous casting machine after pouring for preset time and performing steel drawing, wherein the vibrating parameter of the crystallizer of steel drawing is amplitude +/-2.69 mm, the negative slip time is 0.129 s, the covering slag viscosity of the crystallizer is 0.15 to 0.20 Pa*s and the binary basicity is controlled to 0.85 to 0.95. According to the rare earth heat-resistant stainless steel continuous casting method, continuous casting production of steel grade with rare earth content being more than 0.03percent is realized, two-furnace continuous pouring can be realized, a cold plate of less than 3 mm can be rolled, and the surface quality is high.

Description

technical field [0001] The invention relates to the technical field of steelmaking technology, in particular to a method for continuous casting of rare earth heat-resistant stainless steel. Background technique [0002] Rare earth heat-resistant stainless steel is a new type of alloy steel obtained by adding rare earth elements to steel. By adding rare earth elements to the stainless steel, the inclusions in the stainless steel can be denatured and the harm of the inclusions can be reduced. Secondly, let the rare earth occupy the effective space of the grain boundary, prevent the entry of other impurities, and reduce the segregation of harmful elements at the grain boundary. At the same time, rare earth can also refine grains and control the purity of grain boundaries in steel. Therefore, rare earth heat-resistant stainless steel has better high-temperature creep strength and high-temperature durability than ordinary heat-resistant stainless steel. It is widely used in me...

AI Technical Summary

Problems solved by technology

[0003] Because rare earth elements are easily oxidized, nozzle nodules and clogging are serious during the continuous casting process, which not only affects casting, but also causes violent fluctuations in the liquid level of the mold, partial flow at the nozzle, turbulence in the flow field of the mold, and unstable casting speed. The reaction of the mold flux and the floating of rare earth inclusions into the mold flux lead to the deterioration of the mold flux performance, which not only increases the risk of slag entrainment, but also easily leads to poor lubrication of the billet shell in the mold, forming large turnovers and leaks on the surface of the billet. Steel and other issues

[0004] At present, there is only rare earth steel mold casting method in China, and the continuous casting method is limited to carbon steel with extremely low rare earth content (below 0.03%), and the castability is poor, and heat-resistant stainless steel with high rare earth content has not yet been realized in China. casting production

Images