Effect of Additional Boron Amount on Surface Roughness after Lathe Turning in h-BN Dispersed Type 304 Stainless Steels

Abstract

The authors have reported that the machinability (lathe turning, drilling and sawing) of SUS304 (Type 304) austenitic stainless steel is improved by precipitating hexagonal boron nitride (h-BN). In this study, we investigated the surface roughness after lathe turning in the h-BN precipitated SUS304 steels, where the nitrogen content was fixed at 0.2% and the boron content was changed as 0, 0.03, 0.05, and 0.1% (mass%). Surface roughness increased as the boron content increased, especially at a lower cutting speed of 22 m/min. However, SUS304 steel with boron content of up to 0.05 mass% had similar or smaller surface roughness compared with a commercial SUS304 steel, and the SUS304 steel containing 0.1 mass% boron had smaller surface roughness compared with a SUS303 (Type 303) sulfur-added free-cutting steel. Precipitation of h-BN increased the size of the build-up edge and increased the surface roughness. On the other hand, solute nitrogen increased the Vickers hardness, leading to decreased separation size of the build-up edge and decreased surfaced roughness.

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

“…Stainless steels is an engineering material used in applications where good cost, mechanical strength, wear, good plastic processability and corrosion resistance are required depending on operating conditions [1,2]. AISI 304 stainless steel is one of the widely used chromium-nickel containing stainless steels due to its heat resistance, low temperature resistance, corrosion resistance and mechanical properties [3,4].…”

Enhancement of Mechanical Properties of AISI304 Stainless Thin Plate by Low-pressure, Repeated Explosive Hardening

“…1,2) However, with the development of aerospace industry and improvement of manufacturing technologies, the performance of AISI304 stainless steel treated with common strengthening processes has not met the desired requirements in these fields. [3][4][5][6] Therefore, to explore an effective method to remarkably strengthen the AISI304 stainless steel has become a vital issue.…”