气门精密制造工艺 Valve Precision Manufacturing Process

采用德国进口真空感应熔炼炉，在高真空环境下对特种合金进行熔炼。该工艺可有效去除合金中的气体和非金属夹杂物，使合金成分均匀分布，偏差控制在±0.05%以内。熔炼后的合金材料具有更高的纯度和稳定性，为气门的耐高温、抗疲劳性能奠定基础。

Using imported vacuum induction melting furnace from Germany, special alloys are melted in a high vacuum environment. This process can effectively remove gases and non-metallic inclusions in the alloy, making the alloy composition uniformly distributed with deviation controlled within ±0.05%. The melted alloy material has higher purity and stability, laying the foundation for the high temperature resistance and fatigue resistance of the valve.

采用数控热锻成型技术，通过精确控制锻造温度、压力和模具参数，使气门毛坯获得理想的几何形状和金属流线分布。锻造过程中，金属纤维沿气门轮廓连续分布，未被切断，从而显著提高气门的抗拉强度、屈服强度和抗疲劳性能，比普通锻造工艺产品强度提升25%以上。

Adopting CNC hot forging forming technology, the ideal geometric shape and metal flow line distribution of the valve blank are obtained by precisely controlling forging temperature, pressure and mold parameters. During the forging process, the metal fibers are continuously distributed along the valve contour without being cut, thereby significantly improving the tensile strength, yield strength and fatigue resistance of the valve, which is more than 25% higher than that of products produced by ordinary forging processes.

气门锻件经过真空淬火和回火处理，在真空环境下加热和冷却，避免氧化和脱碳。淬火温度精确控制在850-950℃，回火温度控制在550-650℃，通过优化热处理参数，使气门获得均匀的回火索氏体组织，硬度达到HRC 38-42，同时消除锻造过程中产生的内应力，显著提升气门的抗热变形能力和疲劳寿命。

The valve forgings are subjected to vacuum quenching and tempering treatment, heated and cooled in a vacuum environment to avoid oxidation and decarburization. The quenching temperature is precisely controlled at 850-950℃, and the tempering temperature is controlled at 550-650℃. By optimizing the heat treatment parameters, the valve obtains a uniform tempered sorbite structure with hardness reaching HRC 38-42, while eliminating the internal stress generated during the forging process, significantly improving the thermal deformation resistance and fatigue life of the valve.

采用日本进口五轴联动数控加工中心，对气门杆部、头部和密封面进行精密加工。加工过程中配备在线检测系统，实时监控尺寸精度，确保气门杆直径公差控制在±0.005mm，密封面跳动≤0.01mm，完全满足发动机气门座的装配要求。加工后的气门表面粗糙度达到Ra 0.8μm，有效降低运行过程中的摩擦损耗。

Using imported 5-axis CNC machining center from Japan, the valve stem, head and sealing surface are precision machined. An on-line inspection system is equipped during the machining process to monitor the dimensional accuracy in real time, ensuring that the valve stem diameter tolerance is controlled within ±0.005mm and the sealing surface runout is ≤0.01mm, which fully meets the assembly requirements of the engine valve seat. The surface roughness of the processed valve reaches Ra 0.8μm, which effectively reduces friction loss during operation.