Initial development of thermal and stress fields in continuously cast steel billets

Analysis of Solidification Cracking Using the Specific Crack Susceptibility.

“…The finite element calculation for stress analysis was carried out under the plane strain condition with 2-dimensional slice model. The thermal conductivity of strand and mold were assumed to be 36 W/m K and 380 W/m K. 6,30) Calculation was performed at the condition of casting speed of 1 m/min. The distance from meniscus to mold exit is 770 mm.…”

“…However, the possibility of solidification cracking at various casting speeds, can not be explained by the total crack susceptibility, because the total crack susceptibility decreases with increasing casting speed due to decrease of dwelling time of strand within the mold, as shown in Eq. (6). Generally, the possibility of solidification cracking increases with increasing casting speed in industrial operations.…”

“…The continuous casting process has been mathematically modeled to increase the understanding of the roles of important process variables on the defects. [2][3][4][5][6][7][8][9][10] Despite such intense studies, the thermo-mechanical behaviors of the stand and the mold during continuous casting are not fully understood due to the complex operating conditions of continuous casting process. In particular, a complexity arises in the formation of an air gap between the solidifying shell and the mold wall as a result of thermal and d/g transformation contractions.…”

“…[3][4][5][6][14][15][16][17][18] Previous reports on the cracking condition in continuous casting of steels are listed in Table 1. Clyne et al 14) proposed the crack susceptibility coefficient to estimate the cracking ten-dency during continuous casting of steels.…”

“…16) However, the comparison of the absolute stress and strain values is not enough to investigate the possibility of cracking during continuous casting, because the stress in the solidifying shell changes as a function of temperature and the mushy zone solidifies in almost stress free state, even though the strain occurs in the mushy zone. Kelly et al 6) and Kim et al 17,18) proposed that the solidification cracking occurs in the mushy zone, when the maximum principal stress exceeds the yield stress at that temperature. However, the cracking conditions were estimated in the restricted carbon content range and the same operation conditions.…”