Abstract
This paper describes an extensive study on the effects of C, Nb and Ni on the toughness of heat affected zone of welded joints in low Ni (1.5~3.5%) steels for LPG storage tanks and 9%Ni steel for LNG storage tanks. The toughness of heat affected zone of welded joints is mainly studied with use of the specimens orenared by thermal cycle simulation. The decrease in C content to 0.01 % improves the toughness of fusion line of welded joint of the 2.5% Ni steel, while it deteriorates the toughness of 9%Ni steel. In both steels, the fraction of island martensite in the welded joint decreases, resulting in the improvement of toughness. However, coarsening of microstructure, which lowers toughness, is more extensive for the 9%Ni steel. The difference in microstructure coarsening of both steels seems to be a cause for the difference in the toughness. The addition of 0.03%Nb improves the toughness of the 0.01~0.05%C~2.5%Ni steel through the refining of microstructure, but does not improve the toughness of the 0.01~0.06%C~9%Ni steel. The increase in Ni content from 1.5% to 2.5% improves the toughness of the 0.01%C steel, while a further increase of Ni content to 3.5% lowers toughness. This comes from the intensive formation of island martensite. These results are applied to the production of 0.01%C~2.5%Ni and 0.06%C~9%Ni steels with good toughness of fusion line of welded joints for LPG and LNG storage tanks, respectively.
| Original language | English |
|---|---|
| Pages (from-to) | 229-235 |
| Number of pages | 7 |
| Journal | QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY |
| Volume | 8 |
| Issue number | 2 |
| DOIs | |
| Publication status | Published - Jan 1 1990 |
Fingerprint
All Science Journal Classification (ASJC) codes
- Mechanics of Materials
- Mechanical Engineering
- Surfaces, Coatings and Films
- Metals and Alloys
Cite this
Effects of C, Nb and Ni on the toughness of heat affected zone of welded joints in steels of storage tanks for low temperature use. / Kubo, Takahiro; Furukimi, Osamu; Yamaura, Teruo; Saitoh, Yoshiyuki.
In: QUARTERLY JOURNAL OF THE JAPAN WELDING SOCIETY, Vol. 8, No. 2, 01.01.1990, p. 229-235.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Effects of C, Nb and Ni on the toughness of heat affected zone of welded joints in steels of storage tanks for low temperature use
AU - Kubo, Takahiro
AU - Furukimi, Osamu
AU - Yamaura, Teruo
AU - Saitoh, Yoshiyuki
PY - 1990/1/1
Y1 - 1990/1/1
N2 - This paper describes an extensive study on the effects of C, Nb and Ni on the toughness of heat affected zone of welded joints in low Ni (1.5~3.5%) steels for LPG storage tanks and 9%Ni steel for LNG storage tanks. The toughness of heat affected zone of welded joints is mainly studied with use of the specimens orenared by thermal cycle simulation. The decrease in C content to 0.01 % improves the toughness of fusion line of welded joint of the 2.5% Ni steel, while it deteriorates the toughness of 9%Ni steel. In both steels, the fraction of island martensite in the welded joint decreases, resulting in the improvement of toughness. However, coarsening of microstructure, which lowers toughness, is more extensive for the 9%Ni steel. The difference in microstructure coarsening of both steels seems to be a cause for the difference in the toughness. The addition of 0.03%Nb improves the toughness of the 0.01~0.05%C~2.5%Ni steel through the refining of microstructure, but does not improve the toughness of the 0.01~0.06%C~9%Ni steel. The increase in Ni content from 1.5% to 2.5% improves the toughness of the 0.01%C steel, while a further increase of Ni content to 3.5% lowers toughness. This comes from the intensive formation of island martensite. These results are applied to the production of 0.01%C~2.5%Ni and 0.06%C~9%Ni steels with good toughness of fusion line of welded joints for LPG and LNG storage tanks, respectively.
AB - This paper describes an extensive study on the effects of C, Nb and Ni on the toughness of heat affected zone of welded joints in low Ni (1.5~3.5%) steels for LPG storage tanks and 9%Ni steel for LNG storage tanks. The toughness of heat affected zone of welded joints is mainly studied with use of the specimens orenared by thermal cycle simulation. The decrease in C content to 0.01 % improves the toughness of fusion line of welded joint of the 2.5% Ni steel, while it deteriorates the toughness of 9%Ni steel. In both steels, the fraction of island martensite in the welded joint decreases, resulting in the improvement of toughness. However, coarsening of microstructure, which lowers toughness, is more extensive for the 9%Ni steel. The difference in microstructure coarsening of both steels seems to be a cause for the difference in the toughness. The addition of 0.03%Nb improves the toughness of the 0.01~0.05%C~2.5%Ni steel through the refining of microstructure, but does not improve the toughness of the 0.01~0.06%C~9%Ni steel. The increase in Ni content from 1.5% to 2.5% improves the toughness of the 0.01%C steel, while a further increase of Ni content to 3.5% lowers toughness. This comes from the intensive formation of island martensite. These results are applied to the production of 0.01%C~2.5%Ni and 0.06%C~9%Ni steels with good toughness of fusion line of welded joints for LPG and LNG storage tanks, respectively.
UR - http://www.scopus.com/inward/record.url?scp=85007752903&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85007752903&partnerID=8YFLogxK
U2 - 10.2207/qjjws.8.229
DO - 10.2207/qjjws.8.229
M3 - Article
AN - SCOPUS:85007752903
VL - 8
SP - 229
EP - 235
JO - Yosetsu Gakkai Ronbunshu/Quarterly Journal of the Japan Welding Society
JF - Yosetsu Gakkai Ronbunshu/Quarterly Journal of the Japan Welding Society
SN - 0288-4771
IS - 2
ER -