Modeling High Carbon and High Nickel Steel: Effect of Heat Treatment Time

摘要

In order to understand the effect of heat treatment on the mechanical properties such as the yield strength (5 (02%)), ultimate stress (Su), deformation (d (%)), reduction in area of cross section (RA(%)) and Charpy v-notch test (CVN) values, a neural network analysis approach was undertaken to analyze the data obtained on 10% nickel steel. Initially the neural network was trained using the experimental data collected from 121 data sets from 10 different steel samples that were heat treated at temperatures in the range 950 - 1,050 degrees F, and for up to 1200 minutes. There was insufficient data to run the neural network analysis using the neural mode of analysis. The network analysis was made using the genetic mode over a very small heat treatment range (up to 600 min). The predicted values were then added as additional input to retrain the neural network. By repeating the above procedure three times, final neural network analysis was carried out to predict the properties of steel as a function of heat treatment time (1200 min.). There was not enough data on the CVN values to perform any mode of neural network analysis. The final predictions on the mechanical properties results conclude that the heat treatment at a given temperature (in the range 950 - 1050 degrees F) for up to 300 minutes has some effect on the 5 (02%), Su, d (%), and RA(%) values. However, prolonged heat treatment above 300 minutes and up to 1200 minutes has no significant effect.