Hot Tearing of Fe-18Mn-0.6C-2.6Al High Manganese Steel

Fe-Mn-C-Al high manganese steel has a large tendency to hot tearing, making it difficult to continuously cast and even leading to steel leakage accidents. In this paper, the effects of cooling rate and strain rate on the hot tearing behavior of Fe-18Mn-0.6C-2.6Al (18Mn) steel are investigated. The results show that 18Mn steel is prone to forming multiple cracks. When cracks propagate at higher temperatures, the stress rapidly decreases and exhibits brittle fracture characteristics. However, when the crack propagation temperature is lower, the rate of stress reduction significantly decreases, exhibiting ductile fracture characteristics. The temperature range of hot tearing of 18Mn steel is 1364 °C to 1344 °C, corresponding to the solid fraction of 0.88 to 0.99, and the initial crack propagation stress was 10.73 to 20.03 MPa. It indicates that, with the increase of the strain rate or the decrease of the cooling rate, the cracking temperature increases, and the peak stress decreases. In addition, when the propagation temperature is lower than the solidus, the cracks are no longer called hot tearing, but it will still cause damage in production. This study is valuable for the prediction of hot tearing and process design of continuous casting of Fe-Mn-C-Al high manganese steel.