Properties and Corrosion Resistance of AISI H13 Hot-Work Tool Steel with Borided B4C Powders

• Published in: Metals and materials international 2020, 26(9), , pp.1329-1340
• Main Authors: Günen, Ali, Karahan, İsmail Hakki, Karakaş, Mustafa Serdar, Kurt, Bülent, Kanca, Yusuf, Çay, Vedat Veli, Yıldız, Murat
• Format: Article
• Language: English
• Subjects: Boriding; Boron carbide; Characterization and Evaluation of Materials; Chemistry and Materials Science; Chromium molybdenum vanadium steels; Coatings; Corrosion resistance; Corrosion resistant steels; Dual phase steels; Duplex stainless steels; Electrochemical corrosion; Engineering Thermodynamics; Heat and Mass Transfer; Hot work tool steels; Hot working; Machines; Magnetic Materials; Magnetism; Manufacturing; Martensitic stainless steels; Materials Science; Mechanical properties; Metallic Materials; Microhardness; Processes; Protective coatings; Solid Mechanics; Solid phases; Steam turbines; Surface roughness; Thickness; 재료공학
• ISSN: 1598-9623; 2005-4149
• DOI: 10.1007/s12540-019-00421-0

In this study, the surface of AISI H13 steel was borided with powder blends of B 4 C and NaBF 4 using the powder-pack method at 800, 900 and 1000 °C for 2, 4 and 6 h. The structural and mechanical characteristics of the boride layers formed on the surface were characterized using scanning electron microscopy, energy dispersive spectroscopy, X-ray diffractometry, 2D surface profilometry, microhardness and electrochemical corrosion (3.5 wt% NaCl) tests. The boride layer exhibited a single phase structure (Fe 2 B) in samples coated at 800 °C and a dual-phase structure (FeB + Fe 2 B) at higher boriding temperatures (900 and 1000 °C). The boride layers were compact and crack-free in all boriding conditions. Depending on boriding parameters, the thickness, hardness and average surface roughness (R a ) of the coatings were found to range between 5.81 and 102.46 µm, 1635–1915 HV and 0.315–0.650 µm, respectively. The borided AISI H13 steel displayed up to 33.5 times and 2.4 times higher corrosion resistance than untreated AISI H13 steel and martensitic AISI 431 steel, respectively. This suggests potential use of borided AISI H13 steel in the steam turbines and marine applications as an alternative to the more costly martensitic and duplex stainless steel grades. The corrosion resistance depended on the phase structure (single- or dual-layer), density, thickness and surface roughness of the boride coatings. Graphic Abstract