电沉积Fe-Ni-Cr纳米晶镀层的制备及性能研究

采用脉冲电沉积方法从Cr³⁺溶液中制备Fe-Ni-Cr纳米晶合金镀层,利用SEM,EDS和XRD对Fe-Ni-Cr合金镀层的表面形貌、化学组成和晶粒结构进行观察;利用电化学工作站对镀层进行极化曲线测试并与传统的304不锈钢进行对比。结果表明：电沉积镀层为纳米晶,无裂纹,表面光亮,晶粒尺寸大多分布在10~40 nm之间,镀层主要元素成分含量Cr为25.52%,Fe为59.61%,Ni为6.55%,与传统304不锈钢相比, Fe-Ni-Cr纳米晶镀层在5%的H₂SO₄溶液的自腐蚀电位提高了近30 mV,自腐蚀电流密度降低了近1/8,维钝电流降低了近1/10。因此,Fe-Ni-Cr纳米晶合金镀层表现出更好的耐蚀性。

Preparation and Properties of Electrodeposited Nanocrystalline Fe-Ni-Cr Coating

Nanocrystalline Fe-Ni-Cr alloy coating was plated on brass from a bath containing trivalent chromium plating solution by using pulsed electrodeposition method. Then the surface morphology, chemical composition and microstructure of the coating were characterized by means of SEM with EDS and XRD. The corrosion behavior of the coating in 5%H₂SO₄ solution was examined by polarization curve measurements in comparison to the traditional 304 stainless steel. The results showed that: the electrodeposited Fe-Ni-Cr coating was nanocrystalline with grain size in a range of 10~40 nm and a composition of 25.52% Cr, 59.61% Fe and 6.55% Ni. In 5%H₂SO₄ solution the free corrosion potential increased nearly 30 mV, corrosion current density reduced by nearly 1/8 and passive current reduced by nearly one-tenth for the Fe-Ni-Cr alloy coating in comparison to 304 steel.