Dissimilar Welding in Metalworking

One of our precision metalworking solutions is assembly and welding. Welding is the technique of joining metals or other materials by means of heat or pressure. Modern welding technology first appeared at the end of the 19th century and has developed various welding methods, such as gas welding, arc welding, laser beam welding, etc. Among the metal materials that we commonly use, cast iron is known for its high elongation, and stainless steel is high temperature and corrosion resistant, which is a commonly used metal material under the modern energy-saving trend. Various metals have their own properties, and it is expected to have a hybrid positive effect on the application of products.

For example, one of our renowned Japanese clients had a special parts request for a yacht propulsion device, which uses cast iron and stainless steel in its joint structure. Here is the case study of how we weld two various materials firmly and fulfill the client’s requirements in the actual application.

First of all, after confirming the product specifications, we have added semi-automatic welding equipment. The welding steps are presented and implemented by SOP, and the welding operation is carried out after the environment, specifications, parameters, etc. are confirmed correct. During the welding process, it is also necessary to pay attention to whether there is a discontinuity or abnormal sound, which may be caused by the rust of the welding rod.

If the product is not welded properly, excessive vibration may occur. Further investigation is needed to solve this problem. Through the verification of the Metal Industries Research & Development Centre, MIRDC, we found that once 0.1mm of shrinkage error occurs during welding, it will lead to poor welding quality and cause product vibration.
After clarifying the problem, we added a 0.1mm spacer during welding and changed the material of the welding rod; the poor welding quality no longer occurs. Since then, this product has been one of our stably produced parts for the overseas market.

Through this product case, we have concluded that the design of the welding fixture, the selection of the welding rod, and the welding speed and angle are all factors that affect the welding quality. In the process of assembly and welding, we have a proven product case and have the capability to provide clients with precision metalworking solutions from product design to functional testing.