(二)结构钢、型材和钢板类零件(1)锻件:“桑塔纳”中的锻件,大多采用优质碳素结构钢,此类零件有,模锻曲轴、连杆、连杆盖与进排气门盘部等。锻钢曲轴只用于强化的发动机中,它的材料相当于50~#钢。模锻后正火。材料的化学成份(%): C=0.5;Mn=0.75;Si=0.3;Cr=0.14。轴颈半精磨后,中频滚淬,低温回火。其金相组织,轴颈表面为回火马氏体,向芯部过渡,马氏体逐步减少。 (B) structural steel, profiles and steel parts (1) forgings: “Santana” forgings, most of the high-quality carbon structural steel, such parts are, forging crankshaft, connecting rod, connecting rod cover and intake and exhaust Door Department and so on. Forged steel crankshaft only for enhanced engine, its material is equivalent to 50 ~ # steel. After forging normalizing. The chemical composition of the material (%): C = 0.5; Mn = 0.75; Si = 0.3; Cr = 0.14. After the journal semi-fine grinding, intermediate frequency roll quenching, low temperature tempering. Its microstructure, journal surface for the martensite, the transition to the core, martensite gradually reduced.