摘要
非调质钢具有节约能源、性能优良、降低成本和绿色环保等主要优点,因而得以广泛应用。某汽车公司四缸增压汽油机曲轴材料为铁素体珠光体型的非调质钢,入厂时对曲轴毛坯锻件晶粒度进行控制。为了保证制件最终热处理后具有细晶组织,从而具有所要求的性能指标,要求晶粒度等级5-8级。曲轴毛坯来料检测发现供应商提供毛坯出现晶粒度粗大至3级左右,超出要求范围。为查明晶粒度粗大问题的根本原因对产品的原材料、锻造工艺等进行分析,发现控温冷速慢导致保温时间过长,从而使晶粒度粗大。通过优化控温冷却方式,使晶粒度达到要求范围。
Non quenched and tempered steel has many advantages, such as energy saving, good performance, low cost and green environmental protection, so it can be widely used. The crankshaft material of four - cylinder supercharged gasoline engine of an automobile company is non - quenched and tempered steel with fen＇ite pearlite, and the grain size of crankshaft blank forgings is controlled when entering. In order to ensure that the final heat treatment of the workpiece has fine crystalline structure, so as to have the required performance indicators, the requirements of grain size class 5-8. The material inspection of the crankshaft blank shows that tile supplier provides coarse grain with coarse grain to about 3 grade, which exceeds the required range. In order to find out the root cause of the problem of coarse grain size, the raw material and forging process of the product were analyzed. It was found that the slow cooling rate resulted in the holding time being too long, so that the grain size was coarse. By optimizing temperature control and cooling mode, the grain size can be reached the required range.
出处
《装备制造技术》
2017年第5期110-112,共3页
Equipment Manufacturing Technology
关键词
锻造工艺
锻件
晶粒度
控温冷却
热处理
forging process
forgings
grain size
temperature control
heat treatment
