Enhancement of fatigue endurance by Al-Si coating in hot-stamping boron steel sheet
Document Type
Article
Publication Date
7-1-2019
Abstract
Most structural components undertake cyclic loads in engineering and failures always cause catastrophic economic losses and casualties. In the present work, the phase evolution of Al-Si coating of high-strength boron steel during hot stamping was investigated. Two types of 1500 MPa grade boron steel sheets, one with Al-Si coating and the other without, were studied to reveal the effect on the high-cycle fatigue behavior. The as-received continuously hot-dip Al-Si coating was composed of ?(Al), eutectic Al-Si and ?5. After hot stamping at 1193 K, three phases formed in this coating: ?2, Fe(Al,Si)2 and ?(Fe). The experimental results showed that the endurance limit of the coated steel sheet was 370 MPa under 107 fully reversed tension-compression loading cycles as opposed to 305 MPa in the uncoated sheet. Both the coated and the uncoated specimens showed surface-induced transgranular fatigue fractures. In the uncoated sheet, the fatigue cracks were generated from the decarburization surface, but the Al-Si coating effectively prevented the occurrence of near-surface decarburization during high-temperature hot stamping, and the only cracks in the coated steel sheet were initiated at wire-cutting surfaces.
Recommended Citation
Li, Yuqiang; Tan, Ning; Xu, Zhishuai; Luo, Zhiping; Han, Ke; Zhai, Qijie; and Zheng, Hongxing, "Enhancement of fatigue endurance by Al-Si coating in hot-stamping boron steel sheet" (2019). College of Health, Science, and Technology. 1032.
https://digitalcommons.uncfsu.edu/college_health_science_technology/1032