(1. 湘潭大學(xué) 機(jī)械工程學(xué)院，湘潭 411105；
2. 江蘇工業(yè)學(xué)院 材料科學(xué)與工程學(xué)院，常州 213164；
3. 湘潭大學(xué) 材料設(shè)計(jì)及制備技術(shù)湖南省重點(diǎn)實(shí)驗(yàn)室，湘潭 411105)
摘 要: 利用掃描電鏡及波譜，研究鋅浴中的鈷對(duì)Q235和Q345鋼熱浸鍍鋅層組織及其生長動(dòng)力學(xué)的影響。結(jié)果表明：鋅浴中含0.075%(質(zhì)量分?jǐn)?shù))鈷時(shí)，能完全抑制Q235鍍層組織發(fā)生硅反應(yīng)性；而對(duì)于Q345，則需要在鋅浴中加入0.3%鈷才能部分抑制硅反應(yīng)性；在鋅浴中加入少量的鈷后，鍍層組織中疏松ζ層轉(zhuǎn)變成與液相直接接觸的富鈷ζ相和由消耗δ相生成的致密ζ相；致密的ζ相層阻止液相和δ相的直接接觸；富鈷ζ相可容納大約0.25% Si，避免在固−液界面產(chǎn)生硅的富集，液相通道消失，從而抑制含硅鋼熱浸鍍鋅過程中硅反應(yīng)性的產(chǎn)生。
關(guān)鍵字: 鈷；熱浸鍍鋅；硅反應(yīng)性
galvanizing coating on Si-containing steel
（1. School of Mechanical Engineering, Xiangtan University, Xiangtan 411105, China;
2. School of Materials Science and Engineering, Jiangsu Ploytechnic University, Changzhou 213164, China;
3. Key Laboratory of Materials Design and Preparation Technology of Hunan Province,
Xiangtan University, Xiangtan 411105, China）
Abstract:The effect of Co in Zn bath on the microstructures and growth kinetics of hot-dip galvanized coating on Q235 and Q345 steels were investigated by scanning electron microscopy and wave dispersive spectroscopy (SEM-WDS). The results show that adding 0.075% (mass fraction) Co into the Zn bath can completely inhibit the silicon reactivity in the galvanized coating on the Q235 steel. But for the Q345 steel, to inhibit the silicon reactivity, 0.3% Co should be added into the Zn bath. The loose ζ layer is transformed into the Co-rich ζ layer contacted directly with the liquid phase and the compact ζ layer formed by consuming δ phase after adding a small amount of Co into the Zn bath. The compact ζ layer can prevent the direct contact between the liquid phase and the δ phase. The solubility of Si in the Co-rich ζ phase, which is about 0.25%, can avoid the enrichment of silicon at the boundary between the coating and the liquid, and the liquid channel vanishes. This restrains the silicon reactivity during the hot-dip galvanizing of the Si-containing steel.
Key words: cobalt; galvanizing; silicon reactivity
