热作模具钢表面多元共渗处理的研究.pdfVIP

热作模具钢表面多元共渗处理的研究 摘 要 通过对材料表面强化处理,可以改变材料表面的成分和结构,从而提高表面硬 度。根据实际生产的需求, 选取不同比例的渗氮气氛与渗碳气氛对热作模具钢进行 了离子氮碳共渗表面化学热处理, 对渗层的厚度、硬度、元素成分分布等进行了分 析。利用低温气体多元共渗技术对热作模具钢试样进行处理,对热作模具钢试样进 行 C、N、O 共渗, 实现了在材料表面形成均匀的渗层, 而且渗层又厚又致密。热 作模具钢进行气体多元共渗处理后能形成渗层,通过扫描电镜对渗层的相结构与形 貌进行分析,在材料表面形成了由ε相组成的白亮层和由氮化物组成的扩散层,因 此材料表面硬度增加并随着与表面距离的增加而呈梯度减小。利用低温气体多元共 渗技术对热作模具钢进行了共渗处理,利用扫描电子显微镜和显微硬度计对渗层的 显微组织及显微硬度进行了研究,并讨论了共渗温度和时间对渗层厚度及渗层显微 硬度的影响。结果表明采用低温气体多元共渗技术,在铸钢表面形成了以碳化物和 氮化物为主的合金渗层,不同工艺条件下渗层显微硬度在300 - 700HV变化,加热温 度和保温时间是形成渗层组织结构和显微硬度的主要影响因素。 关键词:热作模具钢，多元共渗，显微硬度 I 热作模具钢表面多元共渗处理的研究 Abstract By strengthening treatment on the surface of materials, the composition and structure of material surface can be changed, and then the hardness of the material surface can be increased. According to the demends of manufacturing practice, this paper has done the surface chemical heat treatment to mould-steel withion nit riding and carburization by choosing different proportion of nit riding atomo sphere and carburization atomo sphere, as w ell as done some analysis and description of the thickness, hardness, elements compo sit ion of the treated layer. The mould-steel can form a layer after gas multielement penetration , the analysis of nit ride layer was made by the SEM about the phase structure and section appearance. The surface of mould-steel can form the white layer composed by phase ε and the diffusion layer composed by nit ride,so the microhardness of surface is raised and came down gradually with the increasing of distance from surface. .Using low temperature gas multi component infiltration technique, carbon, nitrogen and oxygen were infiltrated into the samples of mould-steel ,the thick, dense and ho