Avaliação de soldagem MIG/MAG por curto-circuito utilizando ferramentas computacionais e modelagem estatística

Abstract

In this work, data from MIG/MAG welding experiments carried out in short-circuit operating mode using three gases—100% argon, argon with 25% carbon dioxide, and 100% carbon dioxide—were analyzed, enabling comprehensive analysis of the following parameters: short- circuit time, open arc time, short-circuit voltage, open arc voltage, current rise rate, number of shorts, and reference voltage. During the development of this study, correlation tests (Pearson, Spearman, Kendall) were applied, along with a series of evaluations to assess the quality of models, including the application of Shapiro-Wilk tests to verify the normality of residuals. A correlation matrix was created for the tested parameters and gases. Strong correlations were found between open arc time vs. number of shorts and open arc time vs. current rise rate for all gases. The correlations between current rise rate vs. number of shorts, short-circuit time vs. short-circuit voltage, and short-circuit voltage vs. reference voltage showed lower significance for all gases. Regarding time series analysis, ARIMA and ETS models were fitted and evaluated with specific metrics, indicating the need for model improvements to increase forecast accuracy.