GLASS LUBRICANT FOR HOT EXTRUSION

摘要

PROBLEM TO BE SOLVED: To obtain a glass lubricant for hot extrusion capable of suppressing the scuffing of an extruded tube and the damage of a tool even when high alloy steel or stainless steel is extruded at a high working degree or over a long size. SOLUTION: A specified amt. of B2 O3 is added to an alkali-free silicate glass to obtain the objective glass lubricant. This lubricant preferably contains, by weight, 35-60% SiO2 , 10-20% A12 O3 >12 to <20% B2 O3 15-25% alkaline earth metal oxides and/or ZnO, 0 or <=5% alkali metal oxides and 0 or <=5% P2 O5 .