Applicability of Al-powder-alloy coating to corrosion barriers of 316SS in liquid lead-bismuth eutectic

Kurata, Yuji; Sato, Hidetomo*; Yokota, Hitoshi*; Suzuki, Tetsuya*

A new Al-alloy coating method using Al, Ti and Fe powders has been applied to 316SS in order to develop corrosion resistant coating in lead-bismuth eutectic (LBE). The 316SS plates with coating layers of different Al concentrations were tested at 550C for 1000h in liquid LBE with controlled oxygen concentrations of 1010 mass%. While surface oxidation and grain boundary corrosion accompanied by LBE penetration are observed in 316SS without Al-alloy coating, the Al-alloy coating is effective to protect such severe corrosion attacks in LBE. Although the coating layer containing 2.8 mass% Al does not always keep sufficient corrosion resistance, good corrosion resistance is obtained in the coating layer where the average Al concentration is 4.2 mass%. Cracks are found in the coating layer containing 17.8 mass% Al. The Al-powder-alloy coating applied to 316SS is promising as a corrosion resistant coating method in liquid LBE environment.