17CrNiMo6齿轮钢的组织均匀化

以17CrNiMo6齿轮钢为研究对象,通过对其锻态试样进行不同温度和不同时间的退火处理,采用光学显微镜(OM)、扫描电镜(SEM)、能谱仪(EDS)组织分析手段和Origin数据处理软件,对其带状组织形成原因以及均匀化行为进行了研究与定量分析。结果表明,C、Cr、Ni、Mn和Mo元素在珠光体+贝氏体区域的富集是17CrNiMo6齿轮钢带状组织产生的根本原因,当加热温度为1100 ℃、保温时间为11 h和加热温度为1250 ℃、保温时间为2 h以上时,带状组织已消除,但合金元素不均匀程度仍较高。当加热温度为1250 ℃、保温时间为4 h时,C、Cr、Mn、Ni、P、S、Mo的偏析系数K分别为1.02、0.98、1.02、1.02、1.01、0.98、0.98,元素分布也达到均匀。

Microstructure homogenization of 17CrNiMo6 gear steel

Taking 17CrNiMo6 gear steel as the research object, and the forged specimens were annealed at different temperatures for different time. The formation of the banded structure and its homogenization behavior were studied and quantitatively analyzed by means of optical microscope, scanning electron microscope, energy dispersive spectrometer and data processing software Origin. The results show that the enrichment of C, Cr, Ni, Mn and Mo in the pearlite+bainite region is the root cause of the band structure of the 17CrNiMo6 gear steel. When the heating temperature is 1100 ℃ with the holding time of 11 h, or the heating temperature is 1250 ℃ with the holding time being more than 2 h, the banded structure is eliminated, but the non-uniformity of alloy elements is still high. When the heating temperature is 1250 ℃ and the holding time is 4 h, the segregation coefficients K for C, Cr, Mn, Ni, P, S, Mo are 1.02, 0.98, 1.02, 1.02, 1.01, 0.98, and 0.98, respectively, and the element distribution is also uniform.