Effect of Isothermal Annealing Temperatures and Roller Burnishing on the Microhardness and Surface Quality of H۱۳ Alloy Steel

AISI H۱۳ tool steel is applied widely to produce many kinds of hot work dies, such as forging dies, extrusion dies, die-casting dies and so on. The successful employment of metal in engineering application relies on the ability of the metal to meet design and services requirements and to be fabricated to the proper dimensions. The capability of metal to meet these requirements is determined by mechanical and physical properties of the metal. Burnishing processes is considered as a surface plastic deformation method, which used to improve surface texture (micro hardness, average surface roughness, and maximum surface roughness). This work present the effect of isothermal annealing temperature and roller burnishing process on the surface properties of  H۱۳ alloy steel .This steel was annealed at a different temperatures to get different types of pearlite with different grains and grain size. After that, the steel was burnished with different forces, feeds, and burnishing speeds. The effect of annealing temperatures and roller burnishing on the hardness, micro hardness, average surface roughness and microstructure and metallographic analysis have been investigated. The results showed that roller burnishing could increase the surface hardness under the selected specified conditions depending on the isothermal annealing temperatures by ۱۰۴%, ۴۵% and ۹۰% for the work parts with ۳۰۰۰C, ۵۰۰ ۰C   and  ۶۲۰۰C annealing temperatures respectively. In addition, roller burnishing significantly improves the smoothness of the steel surfaces. The average roughness obtained was ranged from ۰.۱۱μm to ۰.۱۷μm. In this paper, the microstructure analysis, micrograph of the isothermal annealed H۱۳ alloy steel have been given. It has been shown that depending on the isothermal annealing temperature there are different types of grains and grain size of treated steel in pearlite phase.

Keywords:

Annealing , Roller Burnishing , microhardness , Microstructure , Surface roughness