International Journal of Minerals, Metallurgy and Materials
Volume 21, Number 7, July 2014, Page 666
DOI: 10.1007/s12613-014-0956-z
Corresponding author: Qing-xiang Yang E-mail: qxyang@ysu.edu.cn
© University of Science and Technology Beijing and Springer-Verlag Berlin Heidelberg 2014
3D stress simulation and parameter design during twin-roll casting of
304 stainless steel based on the Anand model
Jing Guo
1)
, Yuan-yuan Liu
2)
, Li-gang Liu
1)
, Yue Zhang
3)
, and Qing-xiang Yang
1)
1) State Key Laboratory of Metastable Materials Science & Technology, Yanshan University, Qinhuangdao 066004, China
2) Nanjing Iron & Steel Co., ltd., Nanjing 210035, China
3) School of Material Science and Engineering, University of Science and Technology Beijing, Beijing 100081, China
(Received: 12 December 2013; revised: 13 January 2014; accepted: 16 January 2014)
Abstract: This study first investigated cracks on the surface of an actual steel strip. Formulating the Anand model in ANSYS software, we
then simulated the stress field in the molten pool of type 304 stainless steel during the twin-roll casting process. Parameters affecting the
stress distribution in the molten pool were analyzed in detail and optimized. After twin-roll casting, a large number of transgranular and in-
tergranular cracks resided on the surface of the thin steel strip, and followed a tortuous path. In the molten pool, stress was enhanced at the
exit and at the roller contact positions. The stress at the exit decreased with increasing casting speed and pouring temperature. To ensure high
quality of the fabricated strips, the casting speed and pouring temperature should be controlled above 0.7 m/s and 1520°C, respectively.
Keywords: stainless steel; strip metal; roll casting; stress; surface cracks; numerical analysis
1. Introduction
Twin-roll casting is a sustainable, environmentally
friendly technology that is compatible with iron and steel
recycling [1–4]. However, metal strips fabricated by the
twin-roll strip casting process are prone to cracking. These
cracks seriously degrade the mechanical properties of the
strips, rendering them unsuitable for subsequent processing
and application [5–6]. Cracking of the strip surface is asso-
ciated with the stress state during solidification. Therefore,
the stress in the thin steel strip during twin-roll casting is an
important determiner of strip quality.
To date, most studies on thin steel strips manufactured by
twin-roll casting have focused on the temperature field
[7−8], thermal-flow coupling [9−12] and thermal-me-
chanical coupling [13−14]. Little attention has been paid to
the internal stresses developed in the strip and molten pool
[15−16].
Since few mechanical models of the twin-roll casting
process have been published, simulations are based on nu-
merous assumptions and are consequently imprecise. For
instance, the mechanical behavior of thin steel strips is usu-
ally simulated by the elastic-plastic model, which neglects
physical phenomena as the strip solidifies. To better model
this behavior, new constitutive relations that reflect the
physical phenomena during twin-roll casting should be es-
tablished. Constitutive relationships have been extensively
investigated, and a variety of constitutive models have been
proposed. Among them, the unified Anand model is consid-
ered especially appropriate for many situations [17−18]. Hu
and Ju [19] reported that the Anand model is suitable for
analyzing molten pools and large deformation stresses.
Therefore, in this work, we apply the Anand model to the
stress field in a 3D molten steel pool, and find the optimal
parameters that minimize cracking. Using the simulated re-
sults to guide the actual production, the twin-roll casting
process could be easily and adequately controlled to yield
high-quality products.
2. Experimental
The twin-roll casting machine comprises two rollers,
filled with cooling water, that rotate in opposite directions