Stainless steel corrosion hardening technology developed in Taiwan

The Taiwan Metal Industry Research and Development Center has recently developed a stainless steel corrosion-resistant surface hardening technology that can effectively increase the hardness of stainless steel without affecting the corrosion resistance of stainless steel, solves the problem of plating spallation, and expands the application range of stainless steel. Using this technology to handle stainless steel ball valve, the grade and price are more than 5 times higher than the original.
Due to its corrosion resistance, stainless steel is widely used in the mechanical parts of the chemical, food, machinery and other industrial fields. However, stainless steel is low in hardness and cannot be hardened by heat treatment, so it is often unable to meet industrial use in terms of abrasion resistance and seizure resistance. Requirements, applications are greatly limited.
The new technology mainly uses the plasma depassivation process (a non-polluting dry electroless plating process) to allow medium atoms to penetrate the stainless steel surface to form a modified layer to obtain a relatively high surface hardness. Using this technology to treat SUS304 stainless steel, the surface hardness can be increased from about Hv200 to Hv1300, the corrosion area rate in the 300-hour salt spray test is only 0.1% to 3%, and the corrosion rate measured by the anodic polarization curve can be reduced by 23% to 63. %, the corrosion rate of the hydrochloric acid immersion test can be reduced by 6% to 16%.
Conventionally, the use of salt bath nitriding or ion nitriding to treat stainless steel surfaces tends to result in a decrease in corrosion resistance at the same time as the hardness is increased; if a hard coating is applied by plating or vacuum to increase the surface hardness, although the corrosion resistance is not affected, the coating is applied. Easy to peel.