CAJ | 학술논문

7/8″(22. 225 mm)高温轴承钢钢球在精研工序检查中发现,有若干钢球表面有微小的黑点和麻点. 采用碳硫分析仪、等离子光谱仪、洛氏硬度计、维氏硬度计、金相显微镜、激光共聚焦显微镜及能谱仪对钢球的原材料、显微组织、硬度等进行检验分析,以确定其表面缺陷性质及产生的原因. 结果表明:钢球表面点状或麻点状小黑点缺陷为腐蚀斑点,并非钢球加工过程中产生的机械加工缺陷. 黑点缺陷是由于钢球存放的库房环境比较潮湿而腐蚀的,是钢球疲劳剥落的疲劳源,必须预防和控制.
7/8″(22. 225 mm)고온축승강강구재정연공서검사중발현,유약간강구표면유미소적흑점화마점. 채용탄류분석의、등리자광보의、락씨경도계、유씨경도계、금상현미경、격광공취초현미경급능보의대강구적원재료、현미조직、경도등진행검험분석,이학정기표면결함성질급산생적원인. 결과표명:강구표면점상혹마점상소흑점결함위부식반점,병비강구가공과정중산생적궤계가공결함. 흑점결함시유우강구존방적고방배경비교조습이부식적,시강구피로박락적피로원,필수예방화공제.
Tiny black spots and pits were found on the surface of the high-temperature bearing steel ball of 7/8″(22. 225 mm) in inspection during lapping process. The causes and nature of the surface defects were analyzed with a carbon sulfur analyzer, plasma spectrometer, Rockwell hardness tester, Vicker hardness tester, metallographic microscope, confocal laser scanning microscope and energy spectrometer. The material, microstructure and hardness were tested. The results show that tiny black spots and pits on steel ball surface are corrosion pits, not machining defects. Black spot defects formed due to corrosion in wet environment while the steel balls were stored in the warehouse. Black spot defects can act as fatigue source, so they must be prevented and controlled.