16MnCr5钢形变热处理相变和显微组织研究

PHASE TRANSFORMATION DURING THERMO-MECHANICAL PROCESSING AND MICROSTRUCTURE OF STEEL 16MnCr5

在热模拟机上测试了 16 Mn Cr5钢经 12 0 0℃加热的未变形奥氏体、在 86 0℃经 5 0 %压缩变形奥氏体的 CCT曲线和维氏硬度 ,研究了其相变组织。结果表明 :未变形奥氏体以 0 .0 2 5℃ / s连续冷却时和在 86 0℃变形的未再结晶奥氏体以 0 .2℃ / s连续冷却时及 110 0℃变形的再结晶奥氏体分别以 0 .0 5℃ / s连续冷却和快冷至 6 6 0℃等温退火时均得到多边形铁素体 +珠光体组织。

Investigations were conducted upon transformation and microstructure change of austenite during controlled cooling processes with different prior states.CCT diagrams were determined for austenite without deformation and with 50 % compressive deformation at 860 ℃,respectively,after reheating 1200 ℃.The hardness of the dilatometric specimens was measured and optical micrographs were obtained.The compressive deformation at 860 ℃ promotes polygonal ferrite transformation during continuous cooling.Pearlite+polygonal ferrite are formed in the un deformed and un recrystallized austenite when cooled at a cooling rate no more than 0 025 ℃/s and 0 2 ℃/s,respectively.Pearlite+polygonal ferrite are formed when the steel is continuously cooled at rate no more than 0.05 ℃/s and held isothermally at 660 ℃,after deformation at 1100 ℃ at which austenite is recrystallized dynamically.