Study On The High Temperature Corrosion Property Of The Deposited Metal Of Stainless Steel Coated Electrode

In this article, the history of high temperature oxidation is recalled, its future is forecasted, and the existed experimental researches and practical production experiences are summed up. The results show that it is necessary and urgent to research the super-temperature corrosion behavior of the stainless steel alloying system.In the experiment, the deposited metal of the GBE310-16(A402) stainless steel rested electrode is taken as basic, the content of nickel and chromium is changed and some rare-earth oxide is added in the coating of some electrode These deposited metals with different compositions are tested under super-temperature(13 80℃ and 1280℃ )by oxidation and sulphidizatioa The curve of weight-loss ratio to time is mede by weight-loss method. By optical microscope, scanning electron microscope, energy spectrum analysis, as well as X-ray diffraction, the macro and micro phenomena appeared in the test are analyzed and discussed base on the composition of the deposited metal and the microstruction under high and room temperature.Following conclusion are drawn: (1) In two kinds of high temperature corrosion atmosphere, the brokenways of the corrosion film on the two deposited metals with different compositions are different. With the decrease of nickel content and the increase of chromium content the weight-loss is obviously lowered at the initial stage the high temperature oxidation, and the weight-loss curve is oxidation film are improved. Under the same condition, the weight-loss ratio is obviously decreased and the compactness of surface film is increased in the sulphidization test. (2)The chromium depleted layer is formed under the corrosion film after the high temperature. With the decrease of nickel content, the microstructure is changed from the single phase austenite to austenite and ferrite, and the fommation rate of Cr3O3 film is accelerated owing to the rapid diffusion of chromium, and the content of ferrite is gradually increased from surface to inside (3) After the rear-earth oxide is add to the coating, the ability of resisting high temperature corrosion of its deposited metal is obviously improved .In the high temperature oxidation , the compact and good plastic Cr2Os film is formed on the deposited metal Although the weight-loss ratio in the high temperature oxidation isn't obviously changed, the corrosion deepness is obviously decreaed .In the process of high temperature sulphidization, astable and compact Cr2O3 filmis also formed on the deposited metal, and the chromium-depleted layer doesn't form under the film. The weight-loss ratio in the high temperature sulphidization is obviously lowered, the corrosion deepness is obviously decreasedThe experimental condition and results have some theoretical and practical meanings for the stainless steel weld metal of Fe-Cr-Ni alloying system...