The Research Of Repairing Micro-cracks By Plating On The Steel Blade Surface

Nowadays electroplating technology is one of the main instruments in the field of parts repaired area. By using the electrolysis principle we fabricate other metals or alloys coating on the part surface, so as to restore or improve the Surface properties. With the increasing competition on the manufacturing, the pursuit of the parts’ integrated performance are getting increasingly top, also greater challenges for repair. Currently, in the course of repairing parts studied electroplating technology has been combined with thermal spraying, ion implantation, laser micro-processing surface technology. So kinds of technologies can learn from each other.This paper is mainly targeted at steel impeller which is made in the15Cr2Mo1. By making plating or electroplating combined with other surface techniques, we can repair cracks on the shallow surface of the blade. Experiments can be done in accordance with the following steps. First step, analysis the principle of fatigue crack produced, then use the method of three-point bending to manufacture fatigue crack; Second step, prepare the formula of plating liquid and make coating which have the fixed composition ratio of the alloy; Third step, set technology parameter and develop the reasonable plating process:The fourth step, make metal ion deposited in crack, add metal ion in the crack department constantly to heal the crack:The fifth step, considering the effect of the crack repaired, we decide to make coating combined with laser surface alloy of processing or heat treatment after preparation alloy coating. Thus, the metal ion filled combine with the substrate in metallurgy. Experiments show that when plating combined with laser alloying technology, the coating melting can overcome the deposition heterogeneity problem, also improve the effect of crack repaired. Therefore, combination of two processes can achieve a good complementary roles. It can repair the crack in the shallow surface, at the same time achieve the purpose to improve the surface property. Another technology combination, alloy coating was treated by subsequent heat treatment. The formation of intermetallic compounds in this course increase the strength of coating and substrate in the crack.Through the research of this subject, electroplating technology could be the assist to repair the micro-crack of parts on the shallow surface and recover the original size, also extend life of workpiece. Therefore, the research experience can help us to explore related type techniques of surface repairing which has a more extensive and of great significance.