Optimizing Thermomechanical Processing Routes to Achieve Desired Grain Size in SS 304 Using Response Surface Methodology

Controlling grain size in stainless steel 304 (SS304) is vital for tailoring its properties for specific applications. In this study, we have employed response surface methodology (RSM) to optimize the processing routes to achieve the desired grain size in SS304 through a combination of cold rolling and annealing. By utilizing the face-centered central composite design of RSM, experimental runs were generated, considering % cold rolling and annealing time as the input factors. Subsequently, based on the experimental runs of RSM, SS304 was subjected to cold rolling to a different extent, followed by annealing at a constant temperature for varying durations. As a result of variation in thermomechanical treatment, steels with various grain sizes were developed which is treated as the output of the experimental runs. An analysis of variance (ANOVA) was conducted on the experimental data. Findings show a strong correlation between SS304 grain size, cold rolling reduction, and annealing duration. The proposed model precisely predicts grain size evolution, aiding effective thermomechanical processing optimization which could be useful for various thermomechanical processing industries.