Model development for estimating the aging behaviors of gray cast iron (GCI) alloy at different times and temperatures

摘要

In this study, both quantitative and qualitative approach for estimating the aging behaviors of gray cast iron (GCI) alloy at different times and temperatures was adopted. The data were obtained from laboratory experimental tests conducted to determine the mechanical properties of the produced GCI alloys. Model was developed using linear differential equation to ascertain the degree of certainty of the effect of the variables (time and temperature) on the properties such as hardness, impact toughness, ultimate tensile strength (UTS), and wear resistance (WR) of the GCI alloys. The results of the model validation showed that there is positive association between experimental data and model predicted data, the standard deviation values are much closer to the mean, a positive or direct linear correlation exists between the two data for all the alloys, there is high degree of direct correlation between experimental and model predicted data, the standard errors were less than 10%, and the confidence intervals at 95% confidence level are within the acceptable tolerance. The model therefore was accepted. From the model, a software package was developed using VISUAL BASIC system. It is users friendly and runs on the computers with VISUAL BASIC, MATLAB TOOL, and EXCEL PACKAGES of at least 64-MB RAM and 3.0-GB free hard disk. It can also run on higher-grade computers such as Pentium-3 and Pentium-4.