Study of the Effect of Initial Surface Treatment and Thermal Treatment of Double Hard Chromium Coatings Results of Steel JIS SCM440H

• Main Author: DIKDIK ANDIKA (NIM : 13713057), RIAN
• Format: Final Project
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/30405
• Institution: Institut Teknologi Bandung

Hard chrome coating is applied to engineering components that require high hardness especially for wear resistance. To obtain good coating quality with high hardness and high coat bond strength it is necessary to optimize the coating process. The coating process in this study was done by double plating beginning with pre-treatment on the first layer result with variation; without treatment, sand blasting and shot peening. In addition, annealing thermal treatment (600oC for 1 hour) was applied to the sample to encourage further diffusion of chromium into the substrate to improve chemical bonding. <br /> <br /> <br /> <br /> Variation of pre-treatment was done to know the morphological characteristics of chromium deposit surface. In the surface treatment shot peening obtained the most uniform grain morphology. In addition, the coating surface hardness value from the highest to the lowest consecutive samples without surface treatment, sand blasting treatment, shot peening treatment. While the thermal treatment provides a change in the combination of Cr + Fe elements in sand blasting samples which indicate the diffusion into the substrate, thus indicating an increase in chemical bonding. However, it has microstructural cracks result and a significant effect of decreasing hardness compared to sample hardness without thermal treatment. <br />