3947

3725

كارشناسي ارشد

استخراج فلزات

اصفهان: دانشگاه صنعتي اصفهان، دانشكده مواد

1386

دوازده، 95،[II] ص: مصور، جدول، نمودار

ص.ع.به: فارسي و انگليسي

مهندسي مواد

ID3725

به فارسي و انگليسي: قابل رويت در نسخه ديجيتال

AbstractProduction of nanostructured high nitrogen austenitic stainless steel by mechanicalalloying was investigated The effect of alloying time and atmosphere on the room temptemperature to transformation in Fe 18Cr 11Mn powder mixture was evaluated too Itwas observed that the amount of nitrogen absorption increases by containing 0 65 wt nitrogen was produced after 100 hours of milling While phase is stable up to 100th hourof milling under Ar atmosphere and the phase nucleates after 120 hours of milling Thestructure of the produced steel under both atmospheres was in the range of nanometer Theminimum grain size obtained by milling under N2 atmosphere was smaller than Aratmosphere The X Ray Diffraction patterns showed that austenit is formed after 90 ofthe matrix became amorphous and the grain size reached to 10 nm The results showed thatthe strain of the powder blend decreases by nucleation and growth of the austenite grains After completion of to transformation the mechanical alloying causes to grain growthof the phase The heat treatment of the produced high nitrogen steel showed that it has ahigh thermal stability and the amount of nitrogen before and after heat treatment isconstant Also the possibility of Mn replacement by N was investigated The resultsshowed that it is possible to reduce the amount of Mn in the structure up to 8 weightpercent

محمد حسن عباسي، محمد علي گلعذار

مسعود پنجه ور

مظفري، فتح الله كريم زاده