Abstract: In standard YB/T169-2000, it is defined that the percentage of sorbite in structure of high carbon steel is measured based on the difference structure between bright and dark under optical microscope. In order to analyze the structure corresponding to each bright and dark region under optical microscope t the different region in sample of lead bath annealed Φ0. 9 mm 82A high carbon steel wire with tensile strength 1 296 MPa is marked by microhardness tester and observed by optical and scanning electron microscope, and the reason to occur the bright and dark region is analyzed by different etching method. The results confirm that the bright region and the similar pearlite lamella structure are all sorbite structure. Partial deep-etching leads to false appearance of lamella, and the occurred bright region and similar pearlite are related to the sorbite block which is perpendicular to drawing direction.

Key words: Sorbite, Pearlite, Optical Microscope, Interlamellar Spacing, Orientation

摘要： 标准YB/T169-2000规定,通过光学显微镜中明暗差异测量高碳钢组织的索氏体含量。为了分析光学显微镜中各明暗区域对应的组织结构,对铅浴退火抗拉强度为1 296 MPa的Φ0.9 mm 82A高碳钢丝试样采用显微硬度计做定点标记,使用光学显微镜和扫描电子显微镜进行观察,同时通过不同浸蚀方式分析明暗区域出现的原因。结果证实白亮区域和类似珠光体片层组织均为索氏体组织。局部深腐蚀导致片层假象,而白亮区域和类似珠光体出现均与垂直于拉拔方向索氏体团相关。

关键词: 索氏体, 珠光体, 光学显微镜, 片层间距, 取向