| 摘要 |
PURPOSE:To form a carbide layer having a uniform thickness on a material to be treated and to improve the life of a pot by treating the material in a mixed molten salt bath prepared by adding acidic salt of a Va group element and the Va group element to neutral salt and borate. CONSTITUTION:To a mixed salt bath consisting of 5-30mol% borate and the balance neutral salt are added 2-10wt% acidic salt of a Va group element such as NaVO3 and the Va group element or a substance contg. the element such as Fe-V. This mixture is melted by heating in a pot, and a material to be treated is immersed in the bath, held under prescribed conditions, and subjected to coil quenching or other treatment. By this method the material is coated with VC carbide in a uniform thickness to the uppermost surface of the salt bath. The bath has a slight eroding action on steel, so the life of the pot is elongated. |
