Investigation On Protecting Iron And Steel From High Temperature

Two investigations are included in this thesis. One is "Investigation on protecting iron and steel from corrosion of high temperature aluminum melt", the another is "Investigation on protecting steel and iron from high temperature oxidation", they are the sub-thesis of the general thesis –– "Investigation on protecting steel and iron from high temperature".In the first part, the corrosion characteristics and law of different iron and steel materials in the high temperature aluminum melt are investigated, the viewpoint of the morphology and amount of high carbon phase in iron and steel structure having important effects on their anti-corrosion ability is proposed, the anti-corrosion abilities of several kinds of iron and steel are sorted order so as to provide a scientific gist for factory choosing material of melting aluminum pot. In order to raise the anti-corrosion ability of melting aluminum pot, the TGT-4 composite ceramic protecting coat is used to protect iron pot in the aluminum alloy melting in different factory which use induce furnace, oil-burning furnace, or electric resistance furnace to melt aluminum. The advanced protecting characteristic and long-effect mechanism of TGT-4 coat are analyzed and investigated. A model of iron pot cracking mechanism and related countermeasures are proposed for factory consulting. Based on the situation of the application of TGT-4 having been more and more from day by day, a new principle for choosing material used for the iron pot which melt aluminum alloy is proposed. Combined with production practice, related economic benefit analyses and social benefit analyses are done, and a suggestion for choosing the best material used for iron pot melting aluminum alloy is also proposed.In the nest part, by means of choosing the best materials a new type protecting agent TGM for anti-oxidation in high temperature of steel and iron is made, and a series of protecting test of anti-oxidation in high temperature are done in laboratory condition. The test results shown that: the jetting film of TGM is adhere to steel and iron basis hard, and possessed good high temperature capability, anti-heat shock capability, anti-mechanical shock capability, and enduring capability. The high temperature oxidation contrast test shown that the oxidation rate in high temperature of A3 sample jetted TGM film is tenth of that of A3 sample without jetting film of TGM-4. A suggestion is proposed of applying TGM to melting aluminum pot made of iron or steel for protecting from high temperature oxidation or to other workpiece worked in similar condition, so as to farther improve its composition and characteristics and obtain more economic benefits and social benefits.