The effect of different powder mixtures used in the boriding process on the surface properties of AISI 304 stainless steel material

Abstract

AISI 304 stainless steel, which is used in many areas such as chemistry, petrochemistry, storage tanks and food storage, attracts attention in terms of surface hardness and wear resistance, especially when its industrial applications are evaluated. In this study, it was aimed to improve the surface properties of the AISI 304 stainless steel material used as the substrate material. To develop the best surface properties, boriding layers of varying percentages were created. In order to create these layers, B _4 C, KBF _4 , SiC and graphite powders were compared using variable ratios. Microhardness and wear tests were performed on the borided samples and microstructure examinations were carried out using optical, SEM, XRD and EDX. It has been determined that the B _4 C used as boron source should not be less than 20% for the formation of the boriding layer and the double phase FeB/Fe _2 B. The powder mixture ratio with the highest thickness and hardness value of the boriding layer formed is the powder mixture with 20% B _4 C, 50% KBF _4 , 10% SiC and 20% graphite content. It was observed that the layer thickness increased by 63% and the hardness value increased by 11%. It was observed that this powder mixture gave the lowest wear rate compared to the other powder mixtures in the study. The difference between the highest and lowest wear rate is more than 3 times greater.

Keywords

• AISI 304 stainless steel
• boriding
• microstructure
• hardness
• wear