Boronizing of AISI 316L Stainless Steel Using Spark Plasma Sintering Technique

Abstract

Austenitic stainless-steel has been widely used. Although it offers excellent corrosion resistance, processability, and nonmagnetic properties, it is inferior in terms of wear resistance and hardness. Therefore, the purpose of this study is to form iron boride on an austenitic stainless-steel surface using the spark plasma sintering (SPS) method and to evaluate its properties. The SPS method was utilized because the rapid heating involved in the process reduces the processing time. AISI 316L as a sample material was boronized for 3.6 ks at 1073 – 1273 K at applied pressures of 4 MPa and 8 MPa with a powder mixture of B4C and KBF4. The Vickers hardness profile results showed that the hardness of the untreated sample was ~ 200 HV whereas that of the boronized sample was ~ 2300 HV. The wear test profile showed that the wear resistance of the boronized sample was significantly improved. Moreover, according to elemental analyses, boron diffused from the sample surface to 200 μm and 60 μm when the applied pressure was 8 MPa and 4 MPa, respectively. This indicated that boron diffused to a greater depth when the applied pressure was increased.

Boronizing of CoCrFeMnNi High-Entropy Alloys Using Spark Plasma Sintering

“…These results indicate that the use of SPS accelerated the reaction and shortened the processing time. It has been observed that in the boronizing process using SPS, the boron source powder becomes active when an electric current is applied, and the reaction is accelerated owing to a decrease in the activation energy of the boronizing reaction [20,21]. In this study, the reaction was promoted in the same manner, and it can be considered that a boride layer of the same thickness could be obtained in a shorter time than that of the boronizing treatment using the general powder packing method.…”

“…Using this method, a hard layer with excellent adhesion can be formed. One of the diffusion coating methods is boronizing (boron immersion) treatment, which can form borides with an excellent hardness and wear resistance [18][19][20][21], and this could help overcome the aforementioned limitations associated with HEA. However, in conventional boronizing treatment, the deterioration of the mechanical properties of the base material owing to high temperatures and prolonged treatment is an issue that needs to be addressed [22,23].…”