Surface Hardening of AISI H13 Steel Using Pulsed Plasma Electrolytic Carburizing (PPEC)

Abstract

In this work, the feasibility of a plasma electrolytic carburizing (PEC) treatment on AISI H13 steel using an aqueous solution of C3H5(OH)3, and NaOH was investigated. The substrate samples were biased cathodically to a 20 kW pulsed DC power supply with a variable voltage. The formation of hard carbon‐rich layer on the surface of the treated samples was confirmed by XRD analysis. Metallographic and SEM studies revealed that a uniform and compact nanocrystalline carbon‐rich layer was firmly stuck to the surface of the samples, and no cracks were observed between the carburized layer and the substrate. The coating mechanical performances were evaluated using microhardness tests. The microhardness of the carbon‐rich layer on the substrate was 866 HV, while the hardness of the substrate was 210 HV. Pin‐on‐disk abrasion tests were conducted to evaluate the surface wear resistance. Although all treated samples manifested a magnificent increase in wear resistance, the results showed different resistance in the differently treated samples. The microscopical investigation of the surfaces also showed that the wear mechanism of the tested samples varied by different treatment parameters, especially by the applied frequency. The results also showed that the current pulse frequency significantly influenced both the layer growth kinetics and the coating morphologies.

Plasma electrolytic saturation of steels with nitrogen and carbon

“…The current at frequency of 10 kHz is shown to reduce the crystal size to the nanometre scale and to improve the wear resistance of the material [43].…”

“…This result is obtained at the cathode carburising of steel AISI H13 in electrolyte containing 50% glycerol and 2% NaOH at 150 V and the pulse duty cycle, 90% [43]. Weight loss was measured at the sliding distance of 250 m. The minimal weight loss equal to 0.022 g was observed for the carburised layer obtained at a frequency of 10,000 Hz.…”

AISI 316-L paslanmaz çeliğin yüzey işlemlerinde termo-kimyasal elektrolitik plazma teknolojisinin uygulanması

“…Plazma Elektroliz (PE), genellikle yüksek sıcaklıklarda, arayer elementleri içeren sıvı halde gerçekleştirilen bir elektrotermo-kimyasal difüzyon / saturasyon işlemidir [3,4]. Şimdiye kadar, plazma elektrolitik karbürleme tekniği titanyum [5], düşük karbonlu çelik [6], düşük alaşımlı çelik [7] ve demirli metaller [4,8,9] gibi çeşitli mühendislik malzemeleri üzerinde uygulanmıştır. [10] Elektrolitik plazma difüzyon işlemlerinde, en önemli proses değişkeni çözeltiye ilave edilen kimyasallardır.…”

Investigation of corrosion behaviour of carbon steel coated by pulsed plasma electrolytic boronising technique in 3·5 wt-%NaCl aqueous solution

“…6,7 In this process, the applied voltage determines the surface temperature of the workpieces during the treatment. [7][8][9] This method is relatively low cost and ecologically friendly and non-hazardous in comparison with other electrolytes which might otherwise be considered. 10 The boron diffusion into the surface of metal alloys creates a fully dense zone of metal borides.…”