Microstructure of laser boronized nodular iron

✍ Scribed by Marta Paczkowska; Wiktoria Ratuszek; Włodzimierz Waligóra

• Book ID: 104094945
• Publisher: Elsevier Science
• Year: 2010
• Tongue: English
• Weight: 964 KB
• Volume: 205
• Category: Article
• ISSN: 0257-8972
• DOI: 10.1016/j.surfcoat.2010.09.057

✦ Synopsis

Nodular iron was laser boronized by a CO 2 molecular laser with a continuous wave. Parameters of laser treatment have been selected in an appropriate way to achieve different cooling rates for the melting zone. The surface layer microstructure of nodular iron after laser boronizing has been investigated by optical microscopy, scanning electron microscopy and X-ray diffraction. Different microstructures in melted zones have been observed for different cooling rates. The polygonal shape of the Fe 2 B phase (typical for Fe 2 B after laser boronizing) has been found in the melted zone cooled at 10 3 °C/s. Fe 2 B borides have been confirmed by X-ray diffraction. An ultra-fine microstructure has been found in the melted zone cooled at the rate of 8 × 10 3 °C/s in contrary to the previous one. In this case, the X-ray diffraction revealed higher amounts of hard phases such as Fe 2 B and Fe 3 C. The microhardness of the melted zone cooled at 8 × 10 3 °C/s was approximately 1300 HV0.1 while in the case of 10 3 °C/s the cooling rate microhardness was lower-approximately 1100 HV0.1.