| 摘要 |
PURPOSE:To manufacture stably a steel plate having aimed strength by performing an experiment and investigation about the relation among rolling condition, cooling condition and steel structure, and controlling the rolling and cooling conditions based on said relation in improving the strength of the rolled steel plate by cooling it. CONSTITUTION:In the process for improving the strength by hot rolling the steel plate then cooling it, technics for indicating the steel plate strength after water cooling by the sum of the strength in no water cooling and the raised quantity of the strength due to water cooling are adopted, and a high speed deformation experiment is performed by using a hydraulic servo type testing machine, further the cooling is controlled and detailed correspondence investigation in rolling condition, cooling condition and steel plate structure is performed. The process as the condition determining technic for obtaining the aimed strength based on the experiment and the investigation is developed. According to it, the cooling rate and the temp. of stopping the cooling are determined and performed based on the aimed strength of the steel plate. The fluctuation in strength of steel plates is decreased and the steel plate having stable aimed strength can be manufactured. |
