| 摘要 |
FIELD: metallurgy, in particular, rolling-mill industry, electric-welded pipes for oil pipelines in seismic regions. ^ SUBSTANCE: claimed method includes slab heating, breaking-down to intermediate thickness and finish rolling in regulated temperature region. Slab is heated to 1170-12400C, finish rolling is carried out at 910-7100C with total relative cogging of 60-80 %. In one embodiment of invention low-alloy steel for candies contains (mass %): 0.06-0.12 C; 1.4-1.7 Mn; 0.20-0.45 Si; 0.06-0.10 V; 0.04-0.08 Nb; 0.005-0.035 Ti; 0.01-0.3 Cr; 0.01-0.3 Ni; 0.01-0.3 Ni; 0.01-0.3 Cu; 0.02-0.05 Al; 0.01-0.50 Mo; <=0.006 S; <=0.015 P; <=0.006 B; <=0.010 N; and balance: Fe, provided that C +Mn/6 + (Cr + Mo + V)/5 + (Ni +Cu)/15 = 0.35 - 0.40 % and C + V/10 + Mo/15 + (Cr +Mn + Cu)/20 +Si/30 +Ni/60 + 5B <= 0.22 %. ^ EFFECT: candy with improved mechanical properties and weldability. ^ 2 cl, 3 tbl, 1 ex |
