为提高长型针阀体座面处的渗层深度和硬度,本文进行了针阀体中孔插碳棒与未插碳棒C—N共渗对比试验。实践证明,插碳棒后座面处的渗层深度、硬度及碳化物级别均得到显著提高。共渗后采用空冷淬火,冰冷处理,不仅表面硬度高,而且变形量很小。 In order to improve the penetration depth and hardness at the seat surface of the long needle valve, a comparative experiment on C-N co-permeation between needle-inserted carbon rod and non-inserted carbon rod was carried out in this paper. Practice has proved that insertion of carbon rod rear seat at the depth of infiltration layer, hardness and carbide grades have been significantly improved. After infiltration by air-cooled quenching, cold treatment, not only high surface hardness, but the deformation is small.