9Cr2Mo钢中贝氏体的组织形貌

采用光学显微镜和扫描电子显微镜等技术手段观察了经1100℃奥氏体化的9Cr2Mo钢在不同温度的盐浴中等温淬火后贝氏体的组织形貌。结果表明：9Cr2Mo钢1100℃奥氏体化后，在410℃的硝盐浴中等温得到羽毛状的经典上贝氏体组织，在350℃的硝盐浴中等温得到针状（或片状）的下贝氏体组织；上贝氏体铁素体铁素体是在奥氏体晶界处形核并向晶内生长，碳化物在铁素体条间分布；下贝氏体是在奥氏体晶内形核，碳化物分布在铁素体片中间，碳化物大多数与片条的主轴方向交角排列，但角度不等。

MICROSTRUCTURE AND MORPHOLOGY OF BAINITE OF 9Cr2Mo STEEL

The microstructure and morphology of bainite of 9Cr2Mo steel austenitized at 1 100℃ and isothermally quenched in salt bath at different temperature were studied by metallographic microscope and SEM. The observed results show that upper bainite and lower bainite of 9Cr2Mo steel are obtained after the steel has been austenitized at 1 100℃ and then been isothermally quenched in salt bath at 410℃ and 350℃ respectively. Upper bainitie ferrites nucleate at austenite gains boundary and grow toward austenite gain inner and upper bainitie carbide distribute between bainitic ferrites. Lower bainite ferrites nucleate in austenite gains and lower bainite carbide distribute between bainitic ferrites, furthermore, the angles between lower bainite carbide and the principal axis of the lower bainite are unequal.