Numerical simulation of macrosegregation in continuously cast gear steel 20CrMnTi with final electromagnetic stirring
- PDF / 4,914,401 Bytes
- 13 Pages / 595.276 x 790.866 pts Page_size
- 92 Downloads / 186 Views
(0123456789().,-volV)(0123456789(). ,- volV)
ORIGINAL PAPER
Numerical simulation of macrosegregation in continuously cast gear steel 20CrMnTi with final electromagnetic stirring Sheng-kui Yin1,2 • Sen Luo1,2
•
Wen-jie Zhang1,2 • Wei-ling Wang1,2 • Miao-yong Zhu1,2
Received: 17 January 2020 / Revised: 10 April 2020 / Accepted: 26 April 2020 China Iron and Steel Research Institute Group 2020
Abstract A 3D/2D hybrid multi-physical-field mathematical model, which takes into consideration the thermosolutal buoyance, was developed to predict the macrosegregation of gear steel 20CrMnTi continuously cast by a curved billet caster with size of 160 mm 9 160 mm, and investigated the effect of final electromagnetic stirring (F-EMS) on the fluid flow, heat transfer and solute distribution in the liquid core of continuously cast steel. The results show that the application of F-EMS eliminates the effect of thermosolutal buoyancy on the asymmetric distribution of carbon concentration in the cross section of billet and accelerates the final solidification of resident molten steel in the liquid core of strand, but promotes the negative carbon segregation near the billet center. When the gear steel 20CrMnTi is cast at the temperature of 1803 K and speed of 1.7 m/min, the solidification end advances forward from 9.84 to 9.72 m, and center carbon segregation ratio of billet decreases from 1.24 to 1.17 with the increase in current density of F-EMS from 0 to 350 A. Keywords Gear steel Macrosegregation Final electromagnetic stirring Numerical simulation Continuous casting
1 Introduction Macrosegregation is an inevitable solidification defect of continuously cast steel, because of the solubility difference between liquid phase and solid phase, and the serious macrosegregation has a great effect on the mechanical property and service life [1–3]. From the pioneering works on macrosegregation published by Flemings et al. [4–6] in the late 1960s, macrosegregation became a hot research topic in solidification field and it attracted large interests of researchers to elucidate the formation of macrosegregation in castings and develop effective methods to eliminate the macrosegregation in castings. Till now, a big advance on the control of macrosegregation in castings has been achieved and many techniques have been widely used in the production process. Continuous casting is a major & Sen Luo [email protected] 1
Key Laboratory for Ecological Metallurgy of Multimetallic Mineral (Ministry of Education), Northeastern University, Shenyang 110819, Liaoning, China
2
School of Metallurgy, Northeastern University, Shenyang 110819, Liaoning, China
production process of steel in the world due to high efficiency and low energy consumption, and many countermeasures have been proposed to eliminate the macrosegregation of continuously cast steel [7], such as low-temperature casting [8], intensive secondary cooling or thermal soft reduction [9, 10], mechanical soft/hard reduction [11–15], and mold (M)/strand (S)/final (F) electromagnetic
Data Loading...
