Keywords and Phrases
Charpy Toughness; Hot rolling; Porosity closure; Ring Rolling; SEM AFA; Train Wheel
“Industrially cast AISI 1070 steel wheel pre-forms from Amsted Rail Co. were experimentally hot rolled to simulate the conditions for industrial wheel rolling. Ring rolling of near net shape castings can improve location specific properties by decreasing segregation, closing porosity, and reducing grain size without the use of multiple forging operations in a traditional forging line. As-cast wheel sections were subjected to thermomechanical processing routes using a 2-high rolling mill in a temperature range of 830°C to 1200°C. The goal being to simulate the ring rolling process and optimize benefits of mechanical properties of the as-rolled steel. Charpy V- and U-notch impact tests were conducted at -20ºC and 20ºC, respectively, as a function of thermomechanical processing and notch orientation. Mitigation of cast defects such as inclusions and shrinkage porosity by hot rolling were quantified utilizing scanning electron microscopy and micro-computed X-Ray tomography. Microshrinkage porosity was shown to be virtually eliminated at a 66% reduction. A rolling temperature of 830°C resulted in a 114% increase in KCU at 20°C and 67% increase at -20°C in KCV for L-S impact properties through refinement of prior austenite grain size. Anisotropy related to MnS stringers in the rolling direction were the primary cause for reduction in impact toughness in the T-L orientation although grain texture also likely plays a role. Hot tensile tests performed between 830°C to 1200°C in strain rates of 0.1 to 10 s-1 were utilized to develop a Johnson-Cook Strength model. The experimental parameters determined from the Johnson-Cook model were used as inputs to develop a Finite Element Analysis model of the modified wheel rolling process utilizing FORGE NxT software”--Abstract, page iv.
O'Malley, Ronald J.
Buchely, Mario F.
Materials Science and Engineering
M.S. in Metallurgical Engineering
Peaslee Steel Manufacturing Research Center
Missouri University of Science and Technology
Journal article titles appearing in thesis/dissertation
- Evaluation of notch toughness after simulated ring-rolling of AISI 1070 steel wheel castings
- On the effect of hot rolling on inclusion size and distribution in an AISI 1070 steel
- High temperature Johnson-Cook strength of a high carbon steel
xvi, 133 pages
© 2022 Jacob Michael Summers, All rights reserved.
Thesis - Open Access
Summers, Jacob M., "Experimental optimization of simulated ring rolling operation for heavy rail industry" (2022). Masters Theses. 8098.