以工业含铌X80管线钢为对象，研究了不同Nb含量条件下，焊接热影响区粗晶区中的原奥氏体晶粒和析出的状态；通过对焊接热影响区中粗晶区的热模拟实验，研究了不同热输入下，高Nb管线钢焊接粗晶区的晶粒粗化、显微组织演变、及大角晶界分布等情况。结果表明，高Nb钢的粗晶区范围更窄，粗晶区内的晶粒尺寸更小；经过双道焊的热循环后，高Nb钢粗晶区的析出尺寸更小，没有对韧性有害的大尺寸析出。此外，原奥氏体晶粒的粗化，以及显微组织中大角晶界密度的下降，明显降低了高Nb管线钢焊接粗晶区的韧性。
Industrial X80 pipeline steels with different Nb content were employed to investigate the prior austenite grain and precipitation in coarsegrained welding heat affected zone. In addition, in coarse grain zone of high Nb steel, the evolution of mierostructure and the density of high angle boundaries were focused by thermosimulation tests with different heat inputs. The results indicate that the range of coarse grain zone of high Nb steel is smaller than that of medium Nb steel, therein, the grains also are finer. In intercritically reheated coarsegrained heataffected zone of high Nb steel, the size of precipitated particles are much finer, and large particles which can worsen toughness are not found in this zone after double-welding thermal cycle. The toughness deterioration of coarse grain zone of high Nb steel can be explained by the coarsening of prior austenite grains and density decreasing of high angle boundaries.
参考文献
| [1] | 西气东输二线管道工程用X70直缝埋弧焊管技术条件[S].,2007. |
| [2] | 西气东输二线天然气管道工程用热轧钢板技术条件[S].,2007. |
| [3] | Davis C L;King J E .Cleavage initiation in the intercritically reheated coarse-grained heat-affected zone;Part1:fractographic evidence[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1994,25(03):563-573. |
| [4] | Kim B C;Lee S;Kim N J et al.Microstructure and local brittle zone phenomena in high strength low-alloyed Welds[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1991,22(01):139-149. |
| [5] | KENJI OHYA;JONGSEOP KIM;KEN'ICHI YOKOYAMA;MICHIHIKO NAGUMO .Microstructures Relevant to Brittle Fracture Initiation at the Heat-Affected Zone of Weldment of a Low Carbon Steel[J].Metallurgical and Materials Transactions, A. Physical Metallurgy and Materials Science,1996(9):2574-2582. |
| [6] | Lee S;Kim B C;Kwon D .Fracture toughness analysis of heat-affected zones in high-strength low-alloyed steel welds[J].Metallurgical and MaterialsTransactions A,1993,24(05):1133-1141. |
| [7] | 徐学利,辛希贤,智彦利,周勇.X80管线钢焊接二次热循环粗晶区的韧性和显微组织研究[J].机械工程材料,2005(12):49-52. |
| [8] | Lee S;Kim B C;Lee D Y .Fracture mechanism in coarse grained HAZ of HSLA steel welds[J].Scripta Metallurgica,1989,23(06):995-1000. |
| [9] | Byoungchul Hwang;Yang Gon Kim;Sunghak Lee .Effective Grain Size and Charpy Impact Properties of High-Toughness X70 Pipeline Steels[J].Metallurgical and Materials Transactions, A. Physical Metallurgy and Materials Science,2005(8):2107-2114. |
| [10] | Cahn J W .The impurity-drag effect in grain boundary motion[J].Acta Metallurgica,1962,10(09):789-798. |
| [11] | C. R. Hutchinson;H. S. Zurob;C. W. Sinclair .The comparative effectiveness of Nb solute and NbC precipitates at impeding grain-boundary motion in Nb steels[J].Scripta materialia,2008(6):635-637. |
| [12] | 缪成亮,尚成嘉,曹建平,王学敏,贺信莱.HTP X80管线钢的晶粒细化与组织控制[J].钢铁,2009(03):62-66. |
- 下载量()
- 访问量()
- 您的评分：
-
10%
-
20%
-
30%
-
40%
-
50%