利用金相显微镜、扫描电子显微镜及附带EDS系统和透射电子显微镜研究850MPa级焊缝金属的微观组织,并通过分析焊缝金属凝固和相变过程,研究组织形成机制.发现原δ铁索体柱状晶晶界附近的锰和镍含量高于其心部含量.原δ铁素体柱状晶晶界附近组织由平行板条马氏体组成,板条宽度约为300nm,原δ铁素体柱状晶心部组织由"交织状"板条马氏体组成,板条宽度约为400nm.分析认为造成原δ铁索体柱状晶晶界附近和心部组织差异的重要原因是锰和镍的偏析,而焊缝金属良好的冲击韧性是因为存在30%"交织状"马氏体和一定量残余奥氏体.
The microstructures of 850 MPa grade weld metals were investigated by means of optical microscopy,scanning electron microscopy with EDS and transmission electron microscopy,and it was investigated on formation mechanism of microstructure by analyzing solidification and phase transformation.It is found that the content of Mn and Ni in the prior δ ferrite columnar boundary region(CBR)are more than in the columnar core.The microstructure of the prior δ ferrite columnar boundary region consists predominantly of parallel lath martensite whose width is about 300 nm,while the microstructure of the prior δ-ferrite columnar core also consists mainly of interlaced lath martensite whose width is about 400 am.The important reason that the microstructure of the prior δ ferrite columnar boundary region is different with columnar core is of Mn and Ni segregations.The good charpy impact toughness of weld metal is attributed to 30% interlaced lath martensite and some residual austenite.
参考文献
| [1] | Bose Filho W W;Carvalho A L M;Bowen P .Micromechanisms of Cleavage Fracture Initiation From Inclusions in Ferritic Welds Part Ⅰ.Quantifieation of Local Fracture Behaviour Observed in Notched Testpieces[J].Materials Science and Engineering A,2007,460-461(01):436. |
| [2] | Spanos G;Fonda R W .Microstruetural Changes in HSLA-100 Steel Thermally Cycled to Simulate the Heat-Affected Zone During Welding[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1995,26(12):3277. |
| [3] | G.Thewlis .Weldability of X100 linepipe[J].Science and Technology of Welding and Joining,2000(6):365-377. |
| [4] | K. Junhua;Z. Lin;G. Bin .Influence of Mo content on microstructure and mechanical properties of high strength pipeline steel[J].Materials & Design,2004(8):723-728. |
| [5] | Shanmugam S;Ramisetti NK;Misra RDK;Hartmann J;Jansto SG .Microstructure and high strength-toughness combination of a new 700 MPa Nb-microalloyed pipeline steel[J].Materials Science & Engineering, A. Structural Materials: Properties, Misrostructure and Processing,2008(1/2):26-37. |
| [6] | G. Luxenburger;M. Bockelmann;P. Wolf;F. Hanus;R. Cawelius;J. Buchholz .High strength quenched and tempered (Q + T) steels for pressure vessels[J].International Journal of Pressure Vessels and Piping,2004(2):159-171. |
| [7] | E. KEEHAN;L. KARLSSON;H.-O. ANDREN .New Developments with C-Mn-Ni High-Strength Steel Weld Metals, part A -- Microstructure[J].Welding Journal,2006(9):200-210(s). |
| [8] | Deb P;Challenger K D;Therrien A E .Structure-Property Correlation of Submerged-Arc and Gas-Metal-Arc Weldmerits in HY-100 Steel[J].Metallurgical and Materials Transactions A:Physical Metallurgy and Materials Science,1987,18(06):987. |
| [9] | Fleck N A;Grong O;Edwards G R et al.The Role of Filler Metal Wire and Flux Composition in Submerged Arc Weld Metal Transformation Kinetics[J].Welding Journal,1986,65(05):113s. |
| [10] | Sampath K;Green R S;Civis D A et al.Metallurgical Model Speeds Development of GMA Welding Wire for HSLA Steel[J].Welding Journal,1995,74(12):69. |
| [11] | Fleming D A;Bracarense A Q;Olson D L et al.Toward Developing SMA Welding Electrode L for HSLA-100 Grade Steel[J].Welding Journal,1996,75(06):171s. |
| [12] | Ramirez J E;Liu S;Olson D L .Synergistic Precipitation Strengthening Effects of Copper and Niobium in High Strength Steel Weld Metal[J].Materials Science and Engineering A,1996,15(10):91. |
| [13] | 黄春峰.钢的热处理工艺设计经验公式[J].航空制造技术,2000(04):53-56. |
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