RU2000104844A

RU2000104844A - WELDING STEELS SUITABLE FOR WELDING

Info

Publication number: RU2000104844A
Application number: RU2000104844/02A
Authority: RU
Inventors: Нарасимха-Рао В. БАНГАРУ; Джайоунг КОО; Майкл Дж. Лутон; Клиффорд В. ПИТЕРСЕН; Хироси ТАМЕХИРО; Хитоси АСАХИ; Такуя ХАРА; Есио ТЕРАДА
Original assignee: Эксонмобил Апстрим Рисерч Компани; Ниппон Стил Корпорейшн
Priority date: 1997-07-28
Filing date: 1998-07-28
Publication date: 2001-11-10

Claims

1. Low alloy boron-containing steel having a tensile strength of at least about 900 MPa (130 thousand psi), stiffness measured using a Charpy V-shaped impact test at -40 ^° C (-40 ^° F) of at least about 120 joules (90 lb-ft), and a microstructure comprising predominantly fine-grained lower bainite, fine-grained lath martensite or mixtures thereof, converted from essentially unrecrystallized austenite grains, and into wherein said steel contains iron and with eduyuschie additive in percentages by weight:
from about 0.03% to about 0.10% C,
from about 1.6% to about 2.1% Mn,
from about 0.01% to about 0.10% Nb,
from about 0.01% to about 0.10% V,
from about 0.2% to about 0.5% Mo,
from about 0.005% to about 0.03% Ti, and
from about 0.0005% to about 0.0020% B,
and which further differs in that:
0.3 ≤ Ceq ≤ approximately 0.7, and
Pcm ≤ approximately 0.35.

2. The low alloy, boron steel according to claim 1, additionally containing at least one additive selected from the group consisting of (i) from 0 wt.% To
approximately 0.6 wt.% Si, (ii) from 0 wt.% to
approximately 1.0 wt.% Cu, (iii) from 0 wt.% to
approximately 1.0 wt.% Ni, (iv) 0 wt.% to
approximately 1.0 wt.% Cr, (v) 0 wt.% to
approximately 0.006 wt.% Ca, (vi) from 0 wt.% to
approximately 0.06 wt.% Al, (vii) 0 wt.% to
about 0.02 wt.% REM, and (viii) from 0 wt.% to
approximately 0.006 wt.% Mg.

3. The low alloy boron steel according to claim 1, further comprising a fine-grained cementite deposit.

4. The low-alloy boron-containing steel according to claim 1, additionally containing particles of precipitate of carbides or carbonitrides of vanadium, niobium, and molybdenum.

5. The low alloy boron steel according to claim 4, in which the total concentration of vanadium and niobium is greater than about 0.06 wt.%.

6. The low alloy boron steel according to claim 4, in which the concentration of vanadium and the concentration of niobium is greater than about 0.03 wt.%.

7. The low alloy boron steel according to claim 1, wherein said microstructure contains predominantly fine grained lower bainite.

8. The low alloy boron steel according to claim 1, in the form of a strip having a thickness of at least about 10 mm (0.39 inches).

9. The low alloy boron steel according to claim 1, wherein said steel contains from about 0.05% to about 0.09% carbon C.

10. The low alloy boron steel according to claim 1, wherein said steel contains from about 0.2% to about 1.0% Ni nickel.

11. The low alloy boron steel according to claim 1, wherein said steel contains from about 0.03% to about 0.06% niobium Nb.

12. The low alloy boron steel according to claim 1, wherein said steel contains from about 0.03% to about 0.08% vanadium V.

13. The low alloy boron steel according to claim 1, wherein said steel contains from about 0.015% to about 0.02% of titanium Ti.

14. The low alloy boron steel according to claim 1, wherein said steel contains from about 0.0008% to about 0.0012% boron B.

15. The low alloy boron steel according to claim 1, wherein said steel contains from about 0.001% to about 0.06% aluminum A1.