Dai Liangliang, Zhu Chenglong, Gu Ye, Zhang Jiming. Effect of Niobium on Microstructure of X80 Grade Pipe Line Steel[J]. IRON STEEL VANADIUM TITANIUM, 2019, 40(4): 132-137. doi: 10.7513/j.issn.1004-7638.2019.04.025
Citation:
Dai Liangliang, Zhu Chenglong, Gu Ye, Zhang Jiming. Effect of Niobium on Microstructure of X80 Grade Pipe Line Steel[J]. IRON STEEL VANADIUM TITANIUM, 2019, 40(4): 132-137. doi: 10.7513/j.issn.1004-7638.2019.04.025
Dai Liangliang, Zhu Chenglong, Gu Ye, Zhang Jiming. Effect of Niobium on Microstructure of X80 Grade Pipe Line Steel[J]. IRON STEEL VANADIUM TITANIUM, 2019, 40(4): 132-137. doi: 10.7513/j.issn.1004-7638.2019.04.025
Citation:
Dai Liangliang, Zhu Chenglong, Gu Ye, Zhang Jiming. Effect of Niobium on Microstructure of X80 Grade Pipe Line Steel[J]. IRON STEEL VANADIUM TITANIUM, 2019, 40(4): 132-137. doi: 10.7513/j.issn.1004-7638.2019.04.025
Microstructure of high strength X80 pipeline steels which contain different Nb contents was investigated using optical microscopy and transmission electron microscopy.Second phase particles were analyzed by extraction replica method.Results show that microstructure of low Nb content steel comprises granular bainite and Lath-like bainite,and a few of martensite-austenite（M-A） islands.However,microstructure is consisted of fine acicular ferrite and M-A islands in high Nb content steel.Precipitates in low Nb pipeline steel are large scale cubic TiN particles,however,precipitates of high Nb pipelines steel are mainly the large size duplex type（Nb,Ti）C and fine NbC precipitates.
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