Original Article

Mould heat transfer and friction behavior on the surface of wide and heavy slabs in the presence of longitudinal cracks

¹ School of Mechanical Engineering, Northeast Electric Power University, Jilin 132012, Jilin PR China
² International Shipping Research Institute, Gongqing Institute of Science and Technology, Gongqing City 332020, Jiangxi, PR China
³ School of Materials Science and Engineering, Dalian University of Technology, Dalian 116024, Liaoning, PR China
⁴ Marine Engineering College, Dalian Maritime University, Liaoning, Dalian 116026, PR China

^* e-mail: yuliu@neepu.edu.cn

Received: 13 November 2022
Accepted: 6 March 2023

Abstract

The longitudinal crack is a common and serious defect on the surface of wide and heavy slab. The mould heat transfer and friction characteristics of 28 surface longitudinal cracks are collected and investigated in order to reveal the rule of the surface longitudinal cracks. The results show that the decrease amplitude of temperature in the presence of longitudinal crack is between −4.0 and −22.6 °C, and the increase amplitude of temperature is between 3.4 and 28.2 °C. The decrease of temperature velocity is between −0.4 and −1.5 °C.s⁻¹, while the increase of temperature velocity is between 0.32 °C.s⁻¹ and 1.64 °C.s⁻¹. When longitudinal cracks occur in mould, the heat flux of 21 cases has a decrease more than −0.02 MW · m⁻². There are 18 abnormal fluctuations of mould’s transient friction during occurrence of the surface longitudinal crack, which is more than the stable casting. And there are 85.7% longitudinal cracks, which has an upward trend of friction tension or a downward trend of friction pressure.