| Popis: |
In order to improve the high temperature oxidation resistance, 75 Si-Fe and the silver paint were selected as cast-penetrated agent using the cast-infiltration method to form an aluminum silicon composite layer on the heat resistant steel grate surface. The microstructure and hardness properties of cast-infiltration layer were studied by optical microscope (OM), scanning electron microscope (SEM) with electron dispersive spectrum (EDS), and micro hardness test. The results show that the cast-infiltration layer is composed of ferrite and irregular shape of carbide particles. Most of the carbides are (Fe,Cr)3C and a small amount (Fe,Cr)7C3 also observed in composite layer. The highest micro hardness of fine carbide particles reaches 1253 HV. The optimized silicon content is 50wt%, and the thickness of infiltration layer reaches 0.6mm. |
