Behavior on Plastic Deformation of Thin Steel Strips Coated with Electroless Ni-P

Within the present work deformability of Ni-P coatings was analyzed on thin strips of low carbon steel, coated with Ni-P layers in correlation with their structure and chemical composition. Thin layers of 2-7 μm were made at immersion times of 5, 10 and 15 minutes and a variable pH of between 4 and 6, at a temperature of 80-85 °C. The deformability was analyzed by applying the Erichsen Test, which measures the deep deformation capacity of the metallic materials. Following the analysis was established the Erichsen Index (IE) the most used index for assessing the deformation capacity of the sheets. The microscopic analysis, performed on the surface of maximum deformation, shows a cracking of the layers with a different aspect depending on pH, the duration of deposition and the initial structure of the layer. The results of the Errichsen test show a good behavior at plastic deformation of the strips covered with thin Ni-P layers.