含铈304不锈钢夹杂物改性及耐腐蚀性能优化

 通过在304不锈钢中加入不同含量的铈,研究了铈处理前后钢中夹杂物的变化,并借助于腐蚀失重试验及电化学试验,分析了不同含量的铈处理后钢中夹杂物性质变化对304不锈钢耐腐蚀性能的影响。研究结果表明,未加铈的不锈钢中主要为MnS夹杂及复合氧化物夹杂,夹杂物的平均尺寸为8.6 μm,而钢的自腐蚀电位仅为-348.52 mV。加入稀土铈后,夹杂物逐渐改性成球状或椭球状的含铈夹杂物,平均尺寸有所降低,而不锈钢耐腐蚀性则有所提高。当铈质量分数达到0.012%时,钢中MnS夹杂全部改性成球状含铈夹杂,不锈钢自腐蚀电位高达-311.25 mV,耐腐蚀性能最好。继续增加稀土铈含量,钢中夹杂物的形状变得不规则,尺寸也有所增加,导致不锈钢耐腐蚀性能降低。

Inclusion modification and corrosion resistance optimization of 304 stainless steel containing cerium

The evolution of inclusions in steel before and after the cerium treatment was studied by adding different amounts of cerium into the 304 stainless steel. And the effects of inclusion properties on corrosion resistance of 304 stainless steel were analyzed using the corrosion weight loss experiment and electrochemical experiment. MnS inclusions and composite oxide inclusions mainly existed in the stainless steel without cerium, and the average size of inclusions is 8.6 μm, while the self-corrosion potential of steel is only -348.52 mV. After the addition of cerium, the inclusions are gradually modified into spherical or elliptical inclusions, and the average size is reduced, while the corrosion resistance of stainless steel is improved. When the content of cerium reaches 0.012%, the MnS inclusions in steel are all modified into spherical inclusions containing cerium, and the corrosion potential of stainless steel is as high as -311.25 mV, which has the best corrosion resistance. As the content of cerium continues increasing, the shape of the inclusions in steel becomes irregular, and the size of inclusions also increases, resulting in a decrease in the corrosion resistance of the stainless steel.