Impact of Rolling Conditions on Propagation of a Potential Crack
The paper reveals information about crack behavior during hot rolling o heavy-gauge products.FEM-based mathematical modeling has been used to investigate the impact of crack shape and rolling parameters on the distribution of the principal tensile stress and the Cockroft-Latham racture criterion value and on the crack closing capacity.The results clearly show that the crack shape has the most power ul influence on the observed quantities ollowed by the rolling geometry actors.To ind a critical value of the LCK or a speci ic steel grade and an actual rolling process,a laboratory experiment has been conducted,in which problems related to propagation of initial cracks were detected.It consisted in rolling of wedge-shaped specimens with a notch,which was introduced or the purpose of raising the probability of crack occurrence.In order to ind the Critical LCK value in the area of the notch,an additional computer simulation was per ormed. Results of these experiments led to the conclusion that the steel possesses excellent ormability.The Critical LCK values were up to 300 Mpa,which is,essentially,an order higher than in actual rolling.As the critical value of LCK depends,among others,on the metallurgical characteristics of the metal,the key to the issue is in the steel microstructure.The indings brought the conclusion that in this speci ic case the rolling itsel a ects the crack propagation to a small extent only.The heating process poses a much greater challenge,as it is the likely stage involving the steel overheating.
rolling FEM crack propagation Cockroft-Latham fracture criterion
Richard Fabík Jiri Kliber Sergey Aksenov
VSB-TU Ostrava.,7.listopadu 5,708 33 Ostrava -Poruba,Czech Republic
国际会议
郑州
英文
2007-10-23（万方平台首次上网日期，不代表论文的发表时间）