Fundamental studies on molten aluminum-water explosion prevention in direct-chill casting pits

Explosive interactions between molten aluminum and water have been studied to evaluate the impact of cure times of selected (4) organic coatings on explosion onset. Tests were also conducted to assess durability of partially-cured coatings, and the effect of water temperature. Additionally, tests were conducted to assess the potential for deliberately injected non-condensible gases (NCGs) on prevention of explosive trigger shocks. The impact of using rubber and plastic surface layers was assessed for explosion prevention. The steam explosion triggering studies (SETS) facility was designed and constructed as a rapid-turnaround, cost-effective, and safe means to address these phenomenological issues and to derive quantitative, "practically-fundamental" data for situations covering melt masses relocating over submerged surfaces ranging up to ∼ 1000 kg (2,000 lb.). Test data obtained from the SETS facility correlated extremely well with past industry data. It was found that, explosion onset at short cure times does not correlate linearly with cure times. NCG injection was found to be the most important and overwhelming parameter leading to conclusive explosion prevention, leading to development of a potentially-novel methodology for cost-effective, environmentally benign and conclusive explosion prevention. Limited testing with rubber and plastic surfaces revealed that they too can provide protection from explosions but they pyrolyze extensively. Finally, a range of methods were investigated to enable rapid curing of organic coatings (down from 100+h to less than 15-20 minutes). Of these, it was found that microwave-based technology performed impressively and can bring down the time for full-curing to the 15-20 minute range for a both epoxy and coal-tar based coatings.