Tough heat and wear resistant alloy

摘要

Tough high Ni, high Cr alloy has good heat and wear resistance and is suitable as padding alloy or alloy for guide shoes in inclined hot rolling mills for seamless steel pipe mfr. The alloy contains 0.65-1 wt.% C; 28-39 wt.% Cr; 25-49 wt.% Ni; 0.01-4.5 wt.%, pref. 0.01-3.5 Ti; 0.01-4.5 wt.%, pref. 0.01-3.5 wt.% Al; 0.1-8 wt.%, pref. 0.5-8 wt.% W; 0.1-9 wt.%, pref. 0.5-9 wt.% Mo; and a balance of Fe. The alloy may also contain 0.1-3 wt.% Si; 0.1-2 wt.% Mn; and 1-8 wt.% Co, opt. with the further addn. of 0.005-0.2 wt.% N; 0.01-1.5 Nb; 0.01-1.5 wt.% Ta; 0.001-0.2 wt.% B; and/or 0.001-0.2 Zr. The alloy is mfd. e.g. by 20-30 m min heating at 1400-1700 deg.C in air in an ordinary high frequency furnace. In 60 examples, Vickers hardness was 317-399 at normal temp., 151-265 at 900 deg.C and 139-210 at 1000 deg.C; the normal temp. Charpy impact value was 1.00-2.17 kg.m/cm2; and specific wear tested in normal temp. dry conditions agains SUJ-2 at 0.83 m/sec under a load of 18.2 kg was 0.92-1.99 x 10 power -7. The majority of samples withstood more than 30 cycles of heating for 30 sec to 900 deg.C followed by 20 sec water cooling to 200 deg. C before cracking.