Dissolution of delta ferrite through cyclic treatment and its influence on the hydro abrasive erosion and mechanisms

摘要

This study is intended to remove delta ferrite from the microstructure through cyclic heat treatment to upgrade the hydro abrasive erosion resistance. The elimination of delta ferrite occurred through the dissolution of delta ferrite which started through the atomic diffusion of alloying elements from the grain boundaries. This decreased its content and the size with the number of cycles. The yield strength, tensile toughness, and hardness increased with delta ferrite up to 6.3% while the material removal by hydro abrasive erosion demonstrated just opposite trend. The treated specimen possessed 74% higher erosion resistance than the as-received due to its high hardness and tensile toughness. The electron and atomic force microscopy revealed a ductile mode of erosion in all specimens.