Material Analysis on Rivets of Foreign Surgery Instruments

Chemical compositions, hardness, non-metallic inclusions and microstructure of the rivets of surgery instruments made in foreign advanced countries (Germany and USA) were analyzed in order to solve the problem of easily being etched and existence of color difference between rivets and the riveted parts after nitric acid passivating for the domestic surgery instruments. The results show that in our country surgery instruments were made of 1Cr13 or 2Cr13 steel. However, they were made of easy-machining ferrite or austenite stainless steel in the foreign advanced countries. It was obvious that the corrosion resistance of the easy-machining ferrite or austenite stainless steel was more excellent than 1Cr13 or 2Cr13 steel. At the same time, there were a lot of sulphide inclusions which led to poor light reflection capability of light on the surface in the easy-machining ferrite or austenite stainless steel, so it could eliminate the color difference and make the color of the rivets accordance with that of the riveted parts. Problems of corrosion resistance and color difference were solved at the same time by adopting ferrite or austenite stainless steel as the raw material for the surgery instruments.