Effect of corrosion on IF-Steel in simulated-marine environment via its mechanical properties

The present work is conducted to predict the corrosion behavior of interstitial free (IF) steel by exposing it to a simulated marine environment. The IF-Steel samples are corroded for different duration of exposure time (5, 10, 20, 30, 45, and 60 days) in the salt spray chamber using 5 wt% NaCl solution. The corrosion behavior is analyzed in terms of weight loss, rust constituents, and growth of corrosion pits for different durations. The investigations of corroded samples have been conducted by weight loss measurement, surface pit profile and rust composition analysis. The mechanical properties of corroded samples are also calculated and compared with the base metal. Further, the fracture patterns and fractured surfaces have been analyzed with SEM investigations. It has been found that the corrosion rate increases with exposure time slowly in the initial 10 days and reached to the maximum in 20 days with a faster rate. The rate decreases after 20 days till 45 days and again increases up to 60 days. The weight loss increases continuously with exposure time. A noteworthy increase in average roughness has been found during the 45 and 60 days of exposure time compared with base metal. It has been observed that the mechanical properties are degraded with increase in exposure time. Moreover, for percentage weight loss (wl %) in the range 3 < wl% < 6, the rate of degradation in YS, FS and UTS has been found approximately 5, 2.5 and 3 times respectively as compared to the range 0 <wl%< 3.