1Cr18Ni9Ti激光相变硬化层组织及性能

Microstructure and properties of laser transformation hardening layer on 1Crl8Ni9Ti

为了探讨1Cr18Ni9Ti不锈钢组织及性能的变化,采用激光相变硬化处理的方法,利用扫描电子显微镜、X射线衍射仪、显微硬度计、磨损试验机、恒电位仪等研究了激光相变硬化层的组织及性能。进行了理论分析和实验验证,取得了激光相变硬化层的硬度、耐磨性、耐蚀性数据。结果表明,激光相变硬化层主要由奥氏体、马氏体、Fe-(Cr,Ni)以及Fe等组成。随着激光功率的增大,平均显微硬度先增加后减小,在功率为750W时,平均显微硬度达最大值,为223.5HK;在功率为550W时,耐磨性最好,磨损率为基体的56%。激光相变硬化处理后耐蚀性增强;最小的维钝电流密度是基体的33%,最大的钝化稳定区长度是基体的7倍。这一结果对研究1Cr18Ni9Ti不锈钢组织及性能的转变是有帮助的。

To investigate the change of microstructure and properties, laser transformation hardening was carried out on 1Cr18Ni9Ti stainless steel, and the microstructure and properties of laser transformation hardened layers were investigated by means of scanning electron microscope, X-ray diffractometer, microhardnessmeter, abrasive wear testing machine, potentiostat etc. The hardness, wear resistance, corrosion resistance data of laser transformation hardening layer were obtained by theoretical analysis and experimental verification. The result indicated that the laser transformation hardening layer was mainly consisted of austenite, martensite, Fe-（ Cr, Ni）, Fe etc. With the increase of the laser power, the average microhardness of laser hardening layers increased first and then decreased. The average microhardness reached the highest （223.5HK） when laser power was 750W. Wear resistance reached the best （whose wear rate is 56% of the substrate） when the power was 550W. Corrosion resistance was improved after laser transformation hardening, passivation current density of the smallest dimension was 33% of the substrate, the maximum length of the passive zone of stability was seven times of the substrate. The results are helpful to study the change of microstrueture and properties of l Cr187NigTi stainless steel.