摘要 |
A method and composition for stopping-off nitrogen and/or carbon diffusion into metal surfaces. The composition, which is a mixture of a refractory material selected from the group of zirconium and aluminosilicate, sodium silicofluoride and sodium silicate, is coated onto the metal surface where diffusion is to be prevented. The mixture is cured and the metal part is subjected to elevated temperatures for carburizing, nitriding, or carbonitriding. The coating prevents nitrogen and/or carbon diffusion at the coated area. After treatment the coating is removed.
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