高级检索

    B7螺杆上的螺纹剥落原因分析

    THREAD STRIPPING ANALYSIS ON B7 STUD

    • 摘要: 应用光学显微镜、洛氏硬度计、显微硬度仪和光电直读光谱仪,对表面开裂并严重剥落的B7螺杆及同批经退火、拉拔后原材料的金相组织、洛氏硬度、显微硬度和化学成分进行了分析。结果表明,原材料中存在的夹杂物及带状偏析是引起螺杆纵向开裂的主要原因;原材料退火时引起表面脱碳,使螺杆在进行中频感应淬火时出现了层裂纹,最终因螺杆表面严重剥落而失效。

       

      Abstract: The microstructure,micro-penetration hardness and chemical composition of B7 stud which thread stripped and the same lot number raw material after drawing and tempering were analyzed by means of light microscope,rockwell apparatus,HX-100 micro-hardness tester and Baird DV-6 optical emission spectrometer. The result showed that some microstructure defects in raw material such as banded segregation and inclusion result in the B7 stud longitudinal cracking;the surface decarburization of the raw material made hypo-crack taken place,even the thread stripped.

       

    /

    返回文章
    返回