【摘要】 目前球铁曲轴应用中存在的主要问题是疲劳强度满足不了发动机爆发压力不断提高的要求,以及球铁质量不够稳定。提出了以疲劳强度为核心对曲轴质量进行评估,并通过抗拉强度与伸长率的合理匹配、使用等温淬火、圆角滚压等措施提高球铁曲轴的疲劳强度。为提高球铁曲轴质量可靠性,建议:(1)限定铁液中有害元素的含量;(2)控制原材料质量,并采用感应炉熔炼;(3)对原铁液脱硫,降低其硫量;(4)改进球化、孕育工艺;(5)采用先进检测仪器,提高在线检测水平;(6)重视疲劳性能测试,寻求适合于曲轴的检测方法;(7)开展球铁曲轴强度评价的研究。更多还原

【Abstract】 At present the major problem with the application of ductile iron crankshafts is that their fatigue strength is not enough to meet requirements raised due to the everincreasing of the explosion pressure of engines, as well as the quality of ductile iron castings is not stable. It was suggested to take the fatigue strength as the kernel item to assess the quality of crankshafts, and by measures such as selecting a reasonable match of the tensile strength and the elongation, isothermal quenchhing, round corners rolling and so on to increase the fatigue strength of crankshafts. In order to increase the quality reliability of ductile iron crankshafts, the following suggestions were proposed: (a) restricting content of harmful elements; (b) controlling quality of raw materials and adopting induction furnace for melting; (c) to desulphurizing the base iron to reduce its sulphur content; (d) improving nodulizing and inoculating process; (e) adopting advanced test and measuring instruments to increase the level of on-line control; (f) paying attention to the fatigue properties test and searching test method suitable to crankshafts; (g) conducting the research to reasonably assess strength of crankshafts.更多还原