Steel casting

About: Steel casting is a research topic. Over the lifetime, 1951 publications have been published within this topic receiving 7253 citations.

A Transient Simulation and Dynamic Spray Cooling Control Model for Continuous Steel Casting

Abstract: A two-dimensional heat-transfer model for transient simulation and control of a continuous steel slab caster is presented. Slab temperature and solidification are computed by the model as a function of time-varying casting speed, secondary spray cooling water flow rates and temperature, slab thickness, steel chemistry, and pouring and ambient temperatures. Typically, the solidification path, temperature-solid fraction relationship, is prescribed. However, if these data are not available, a microsegregation solidification model that approximates the effects of steel chemistry and cooling rate is incorporated in the caster model. Measured slab surface temperatures recorded from an operating caster are compared with predictions from the transient model. These demonstrate that the model typically can predict the temperature response at the slab surface within 30 °C. Results of several simulations are given to demonstrate the effects of changing casting conditions on the slab thermal profile, end of liquid pool, and solidification end point. A control methodology and algorithm suitable for online control of a continuous casting machine is described, and the ability to control the surface temperature profile by dynamically adjusting secondary spray cooling flow rates is demonstrated by simulation. Results from a preliminary version of the model that is capable of running in real time are presented and are compared with the slower, but more realistic, version of the model.

Development of fluoride-free mold powders for peritectic steel slab casting

Abstract: In this paper, titanium-bearing blast furnace slags (CaO–SiO2–TiO2) produced at Panzhihua Iron and Steel Company (P. R. China) is used as the base material to develop fluoride-free (F-free) mold powders to improve the heat transfer between the mold and the strand. Effects of the binary basicity (CaO/SiO2), TiO2, Na2O, Li2O, MgO, MnO and B2O3 on the melting temperature, viscosity and heat flux of F-free mold powders are investigated. The laboratory results indicate that 1) the melting temperature and the viscosity of the F-free powder decrease, as expected, with increasing the content of Li2O, B2O3 and Na2O respectively, but the lowest viscosity is achieved with 6.0 mass% TiO2; 2) the heat flux of the F-free slag film with 1.0–6.0 mass% TiO2 is close to that of a conventional mold slag film with 2.0–10.0 mass% F; 3) the effect of basicity of the F-free powder on the heat flux is the same as the powder bearing fluoride; 4) the heat flux changes significantly with more than 8.0 mass% Na2O and about 4.0 mass% MnO, whereas the effects of Li2O and B2O3 in the F-free powder on heat flux are not significant. The suitable range of main components of the F-free powder with TiO2 is proposed for casting peritectic-grade-steel slabs. The industrial trials of peritectic steel casting, using the proposed F-free flux, reveals a good surface quality of the slab, and well-controlled heat transfer at the continuous casting mold by the F-free powder with the precipitated crystalline phase being perovskite (CaTiO3) instead of cuspidine in the conventional mold slags that contain fluoride.

Prediction of dendrite arm spacing for low alloy steel casting processes

Abstract: Simple mathematical expressions to predict the primary dendrite arm spacing (PDAS) and secondary dendrite arm spacing (SDAS) suitable for steel casting processes are presented. The equations of the PDAS and SDAS were based on previously published experimental data for low alloy steels. Good agreement was obtained between previous measurements of dendrite arm spacing (DAS) and the model predications in the range of cooling rate occurring in steel casting processes. The results indicated that the cooling rate and carbon content basically govern the calculation of PDAS, especially for low carbon steel. However, the carbon content governs the selection of mathematical expression to predict SDAS for low alloy steels. Dendritic growth is the most common crystallization mechanism in industrial steels. Many empirical expressions have been employed to correlate the PDAS and SDAS with growth rate, temperature gradient, cooling rate, and local solidification time. However, the comparative advantages of the various expressions with respect to the accuracy with different types of steels remain unclear. Thus, the aim of the present study is to develop simple expressions to predict DAS as a function of carbon content and thermal conditions of low alloy steels.

Nucleation, Growth, Transport, and Entrapment of Inclusions During Steel Casting

Abstract: The nucleation, growth, transport, and entrapment of nonmetallic inclusions during the steel casting process are briefly reviewed in this article. The current main research accomplishments as well as future topics that should be focused on in this field are summarized.