不锈钢中铁素体与奥氏体组织转变模拟.pdf

2 8 4 Vol . 2 8 No . 4 2 0 0 7 8 TRANSACTIONS OF MATERIALS AND HEAT TREATMENT August 2 00 7 D 梁晓军, 焦四海 ( , 201900 : , 950 e , Dictra , 900e 1100e , , 900e 950e , 1100 e 2819h, 616h, 318h, : ; ; ; : TG11115 : : 10092 6264( 2007 042 01442 05 Simulations of tr an sformation fr om D2fer rit e t o austenite in stainless st eel LIANG Xiao2jun , JIAO Si2hai (Metallurgical Process Department , Baosteel Research Institute, Shanghai 201900, China Abstr act : To investigate the effect of holding temp erature and time on phase transformation, isothermal heat2treatments were made on stainless steel.The microstructure of the steel isothermally treated at 950e were quantitatively analyzed and compared to the simulating results by Dictra software. The simulating results approximate the exper imental results with an appropriate modeling. Based on those results, more simulations were made for the steel treated at 900 e , 1100e and with different initial grain sizes. The simulating results show that phase transforming driving force is controlled by grain growth at initial stagewhen isothermal temperature are 900e and 950 e , however , grain boundary movements are controlled by alloy elements diffusion at 1100 e . For these three temperatures, it needs 2819h , 61 6h, and 31 8h for D2 ferrite to be completely dissolved, respectively . The simulating results also indicate that grain size has an important effect on velocity of phase transformation . Key wor ds: stainless steel; computer simulation; microstructure transformation; volume fraction , , ThermoCalc , [2, 3] ,