Analysis of Overtemperature Explosion Mechanism of Aluminum Alloy Heat Treatment With Nitrate and Suggestions on Safety Control
To explore the causes and mechanisms of overtemperature explosions in molten nitrate heat treatment processes,and accurately locate the key factors that may cause explosions in aluminum alloy nitrate heat treatment processes,this study refered to national standards,material safety technical instructions,and other materials,took the mixed nitrate of 50wt%po-tassium nitrate and 50wt%sodium nitrate as the heating medium,and conducted aluminum alloy heat treatment process,mixed nitrate heating test,and mixed nitrate and aluminum alloy co-heating test.Proposed safety control measures from three aspects are controlling temperature,avoiding fully enclosed equipment,and strengthening on-site ventilation.The results show that the mixed nitrate has no explosive hazard characteristics in an overtemperature state(600~900℃).After reaching 780C,a nitrate mixture containing aluminum alloy will undergo violent combustion reactions and hot substance splashing,without directly exploding.After reaching a certain temperature,a mixture of nitrate containing aluminum alloy may generate gas due to the decomposition of nitrate itself or violent combustion reaction with aluminum alloy.When the gas accumulates and the pressure exceeds the equipment's pressure limit,a physical explosion may occur.
binary molten nitratealuminum alloyheat treatmentexplosionsafety production management