NI-CR ALLOY LOW IN EXPOSING PROPERTY AND GOOD IN ALKALI CORROSION RESISTANCE

摘要

PURPOSE: To provide an alloy low in exposing properties and excellent in alkali corrosion resistance. ;CONSTITUTION: (1) This cover is an Ni-Cr alloy having a chemical compsn. constituted of, by weight, 0.012 to 0.070% C, ≤1.0% 0.50% Ti and the balance Fe with inevitable impurities, in which Cr carbides are precipitated in the grain boundaries as well as a structure free from Cr depleted layers is formed in the vicinity of the above grain boundaries and having low exposing properties and good alkali corrosion resistance. In addition to the above components, alone or in total, 0.5 to 5.0% of one or more kinds among Mo, W and V may furthermore be incorporated therein. (2) The allay having the above chemical compsn. is subjected to prescribed working and is thereafter subjected to primary heat treatment of holding the above alloy to the temp. range of the perfect soln. temp. (T°C) of the carbides in the alloy or above to T+100°C or below for ≥1min and secondary heat treatment at a temp. and for holding time in the shadowed portion shown by the figure.;COPYRIGHT: (C)1993,JPO&Japio