【摘要】 利用显微硬度计、金相显微镜、透射电子显微镜等方法研究了25Mn Cr Ni Mo钢等温转变贝氏体组织形态的变化规律.显微组织分析表明,300℃等温转变得到下贝氏体组织,之后随着等温转变温度的提高,贝氏体中的铁素体条变粗,逐渐形成粒状贝氏体,420℃等温获得全部的粒状贝氏体组织,随温度继续升高,出现羽毛状组织,得到上贝氏体组织.即随着等温转变温度的升高,贝氏体组织形态由下贝氏体—粒状贝氏体—上贝氏体逐渐演变.在300℃等温转变得到下贝氏体显微硬度最高,随着等温转变温度的提高硬度下降,但390℃以上温度等温所得到贝氏体的硬度较低且随等温温度升高硬度变化不大.更多还原

【Abstract】 A 25 Mn Cr Ni Mo steel is studied on the relationship between isothermal quenching and transformation of bainite morphology by optical microscope,microhardness tester,TEM analysis and other methods.Studies show that the highest microhardness is obtained with the isothermal temperature of 300℃ then it drops sharply with the increase in the isothermal temperature. The microhardness levels off after 390℃,and the lowest microhardness is obtained with the isothermal temperature of 420℃. The bainite morphology is gradually transformed from lower bainite to granular bainite and to upper bainite with the improvement of isothermal transformation temperature.更多还原