Xiaohuai XUE
,
Luhai WU
,
Bainian QIAN
,
Jingli LI
,
Songnian LOU
材料科学技术（英文）
X80 pipeline steel produced by TMCP has high strength and high toughness with ultrafine grain microstructure. The microstructure coarsens and the toughness worsens at the coarse grained (CG) HAZ apparently after weld simulation. The experimental results indicated that the bainitic ferrite and the second phases formed at cooling are differently as the variation of carbon in base metal. In low carbon steels, the bainitic ferrite laths are long and narrow, the second phases are complex including residual austenite, martensite, the M-A constituent and the Fe3C carbide. The formation of Fe3C carbide is the main reason of the poor toughness in CG HAZ. The ultralow carbon in base metal, however, can improve the CG HAZ toughness through restraining the formation of carbides, decreasing the M-A constituent, increasing the residual austenite content, which are beneficial to the CG HAZ toughness.
关键词:
X80 pipeline steel
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null
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null
,
null
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汪文云
,
张朝晖
黄金
doi:10.3969/j.issn.1001-1277.2008.06.003
通过对贵州水银洞卡林型金矿苔藓植物野外全面调查,发现贵州水银洞金矿共有苔藓植物15科42属102种,其中苔类植物4科4属5种,藓类植物10科37属96种,角苔类植物1科1属1种. 短柄小曲尾藓Dicranella gonoi Card.、纤毛丝瓜藓Pohlia hisaet. Kop et J.S.Lou、纤枝短月藓Brachymenium exile (Doz.et.Molk) Bosch et Lac.、真藓Bryum argenteum Hedw.为该矿区裸地大量生长的种类,可利用它们作为金属矿山生态恢复进一步研究的素材.通过与露天开采的金矿区苔藓植物丰富度比较,埋藏型金矿区的苔藓植物较露天开采的金矿区的丰富.该区苔藓植物区系地理成分共9种,世界广布和中国特有分布占主要优势(各22种,都占21.57%),其次是东亚成分(共17种,都占16.67%),再次为热带亚洲成分(共16种,都占15.69%).
关键词:
苔藓植物
,
丰富度指数
,
区系
,
水银洞卡林型金矿
