纳米化对K38G合金900℃涂盐热腐蚀行为的影响

THE EFFECT OF NANOCRYSTALLIZATION ON HOT CORROSION BEHAVIOR OF K38G ALLOY AT 900℃

通过磁控溅射方法在K3 8G合金上沉积了一层与其同成分的纳米晶涂层 .研究了铸态K3 8G合金及其纳米晶涂层在 90 0℃的涂盐 (盐的成分为 75 %Na2 SO4 + 2 5 %K2 SO4 )热腐蚀行为 .结果表明 :当涂薄盐膜时 ( 0 8mg/cm2 ) ,纳米晶涂层表面生成一层连续的Al2 O3膜 ,消除了内硫化 ;当涂厚盐膜时 ( 3mg/cm2 ) ,纳米晶涂层表面氧化产物为Al2 O3、Cr2 O3和TiO2 混合氧化物 ,虽然没有消除内硫化 ,但纳米晶涂层仍然提高了合金的抗热腐蚀性能 .

The sputtered nanocrystalline coating of K38G alloy was obtained by magnetron sputtering.The effect of nanocrystallization on the hot corrosion behavior of K38G alloy at 900℃ was studied.The results indicated that the internal sulfidation was eliminated for the coating by pre-deposition with 0.8 mg/cm 2 of 75%Na_2SO_4+25%K_2SO_4.Although the internal sulfides were still formed for the coating by pre-deposition with 3 mg/cm 2 of 75%Na_2SO_4+25%K_2SO_4,the hot corrosion resistance of K38G alloy was clearly enhanced through nanocrystallization.The hot corrosion mechanism was proposed.