Development of aluminum-alloy coating on type 316SS for nuclear systems using liquid lead-bismuth

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

An Al-alloy coating method using Al, Ti and Fe powders and the laser beam heating has been developed for nuclear systems using liquid lead-bismuth eutectic (LBE). The main defects formed in the Al-alloy coating process are surface defects and cracks. Conditions required to avoid such defects have been studied. A static corrosion test was conducted in liquid LBE at the controlled oxygen concentrations of 10 to 10 wt% at 550C for 3000h. The Al-alloy coating layer on 316SS prevents severe corrosion attack such as Ni dissolution, partial loss of grains and LBE penetration observed in the 316SS without Al-alloy coating. The Al-alloy coating layer, which is formed without surface defects and cracks under the optimum condition, exhibits good corrosion resistance in liquid LBE.