本文選題：脈沖電鍍 + Ni-Cr-Mo合金鍍層�。� 參考：《華北理工大學(xué)》2017年碩士論文

【摘要】：為提高Q235鋼的耐海水腐蝕性能,采用脈沖電鍍法在Q235鋼表面制備了Ni-Cr-Mo合金鍍層。采用輝光放電光譜儀、掃描電鏡、貼濾紙法、塔菲爾曲線和電化學(xué)阻抗譜研究了鍍液組分、檸檬酸銨含量、尿素含量、鍍液溫度、p H值、平均電流密度、占空比和施鍍時(shí)間對(duì)鍍層元素組成、沉積速率、表面形貌、孔隙率和耐蝕性的影響,確定了最優(yōu)鍍液組成和最優(yōu)工藝參數(shù)。最優(yōu)鍍液組分Ni SO4·6H2O、Cr Cl3·6H2O與Na3Mo O4·2H2O摩爾濃度比為10:1:1,最優(yōu)檸檬酸銨含量為0.6 mol·L-1,最優(yōu)尿素含量為1.0 mol·L-1。最優(yōu)工藝參數(shù)分別為鍍液溫度30℃、p H值3.5、平均電流密度10 A·dm-2、占空比0.2、施鍍時(shí)間50 min。采用直流、單脈沖和換向脈沖三種電沉積方式制備的合金鍍層中,換向脈沖方式制備的Ni-Cr-Mo合金鍍層表面粗糙度最低,耐蝕性最好。采用極化曲線、循環(huán)伏安曲線、電化學(xué)阻抗譜和計(jì)時(shí)電流曲線研究了Ni-CrMo合金的電沉積行為。檸檬酸鹽-尿素體系Ni-Cr-Mo合金沉積為受擴(kuò)散控制的不可逆過程,存在活性中間產(chǎn)物在電極表面的吸附,存在形核過程。
[Abstract]:In order to improve the corrosion resistance of Q235 steel, Ni-Cr-Mo alloy coating was prepared on Q235 steel surface by pulse electroplating. The composition of bath, ammonium citrate content, urea content, bath temperature and average current density were studied by means of glow discharge spectrometer, scanning electron microscope, filter paper method, Tafel curve and electrochemical impedance spectroscopy. The effects of duty cycle and plating time on the element composition, deposition rate, surface morphology, porosity and corrosion resistance of the coating were investigated. The optimum bath composition and process parameters were determined. The molar ratio of Ni so 4 6H 2O to Na 3MoO 4 2H 2O is 10: 1: 1, the optimum ammonium citrate content is 0.6 mol L -1 and the optimum urea content is 1.0 mol L -1. The optimum process parameters are as follows: bath temperature 30 鈩，

本文編號(hào)：2037955