Rare earth heat-resistant stainless steel continuous casting method

Abstract

The invention discloses a rare-earth heat-resistant stainless steel continuous casting method, which comprises: selecting an alloy steel with a preset mass percentage. Feed pure Ce rare earth wire into the molten steel in the LF refining furnace, and the feeding amount is determined according to the weight of the molten steel. After the wire feeding is finished, carry out argon blowing and stirring. Seal the contact surface between the tundish cover and the tundish with refractory mud, and seal all the openings on the tundish with ceramic fiber boards, inject argon gas to exhaust the air in the tundish. The continuous casting ladle is poured, and the amount of molten steel in the tundish and the temperature of molten steel are controlled within the preset range. Open the tundish stopper mechanism to pour molten steel into the crystallizer, and start the continuous casting machine to draw steel after casting for a preset time. The crystallizer vibration parameters of the drawn steel are amplitude ±2.69mm, negative slip time 0.129s, mold flux viscosity 0.15‑0.20Pa.s, and binary basicity controlled at 0.85‑0.95. The rare earth heat-resistant stainless steel continuous casting method of the present invention realizes the continuous casting production of steel grades with a rare earth content of more than 0.03% in the steel, can realize continuous casting of two furnaces, and can roll a cold plate with a thickness of less than 3mm, and has good surface quality.

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