窄间隙焊接技术作为一种高效焊接方法以其大大降低熔敷量和节约制造时间的优点，使其在大厚度构件制造中具有广阔的应用前景，但是焊接过程的稳定性及侧壁熔合等缺陷的存在，成为影响构件高品质制造的关键问题。利用深窄间隙埋弧焊接方法成功制造了外径尺寸为2 500 mm，厚度达150 mm的转子模拟件，采用多层双道焊接方法，实现了良好的侧壁熔合效果，且未发现夹杂等缺陷，表面该焊接接头具有较高的成形质量。基于该焊接接头开展冲击韧度、拉伸等力学性能试验，表明该接头的力学性能完全满足使用需求。从而验证了深窄间隙焊接技术在大厚度核电转子焊接中应用的可靠性。
As a high efficiency welding method, narrow gap welding(NGW) technology has many advantages like reducing deposition amount and save manufacturing time, which makes NGW has bright future in manufacturing large scale component with heavy section. However, the welding process stability and fusion of sidewall with base metal(BM) become big issue in making high quality welded joint. A mock-up of rotor with a diameter of 2 500 mm and 150 mm thickness is successfully welded with deep-narrow gap submerged arc welding (DNG-SAW) method. The weld quality could meet the requirement with good fusion of sidewalls of BM without other defects. Based on this welded joint, some mechanical properties such as impact toughness, tensile and hardness teat are carried out to quality the reliability of welded joint. The results show that all the mechanical properties could meet the requirement of design, which further proves that DNG-SAW is effective to weld big component with heavy section.
[1] STANISA B，SCHAUPERL Z，GRILEC K. Erosion behavior of turbine rotor blades installed in the Krsko nuclear power plant[J]. Wear，2003，254(7)：735-741.
[2] TAN L，ZHANG J，ZHUANG D，et al. Influences of lumped passes on welding residual stress of a thick-walled nuclear rotor steel pipe by multi-pass narrow gap welding[J]. Nuclear Engineering and Design，2014，273：47-57.
[3] LIU P，LU F，LIU X，et al. Study on fatigue property and microstructure characteristics of welded nuclear power rotor with heavy section[J]. Journal of Alloys and Compounds，2014，584：430-437.
[4] ZHU M，WANG D，XUAN F. Effect of long-term aging on microstructure and local behavior in the heat-affected zone of a Ni–Cr–Mo–V steel welded joint[J]. Materials Characterization，2014，87：45-61.
[5] 郑韶先，李德福，朱亮，等. 超细颗粒焊剂约束电弧用于超窄间隙的焊接[J]. 机械工程学报，2011，47(8)：83-87. ZHENG Shaoxian，LI Defu，ZHU Liang，et al. Constricted arc by ultra-fine granular flux applied to ultra-narrow gap welding[J]. Journal of Mechanical Engineering，2011，47(8)：83-87.
[6] 兰虎，张华军，陈善本，等. 窄间隙MAG 焊电弧声与电弧作用位置的相关性[J]. 机械工程学报，2014，50(24)：38-43. LAN Hu，ZHANG Huajun，CHEN Shanben，et al. Correlation of arc sound and arc-sidewall position in narrow gap mag welding[J]. Journal of Mechanical Engineering，2014，50(24)：38-43.
[7] MCPHERSON N，BAKER T，LI Y，et al. High dilution submerged arc welding of Cr-Ni-Mo austenitic stainless steel[J]. Science and Technology of Welding and Joining，2000，5(1)：35-39.
[8] RAMAKRISHNAN M，MUTHUPANDI V. Application of submerged arc welding technology with cold wire addition for drum shell long seam butt welds of pressure vessel components[J]. The International Journal of Advanced Manufacturing Technology，2012，65(5-8)：945-956.
[9] VANNOD J，BORNERT M，BIDAUX J，et al. Mechanical and microstructural integrity of nickel–titanium and stainless steel laser joined wires[J]. Acta Materialia，2011，59(17)：6538-6546.
[10] KANG D，LEE H. Effect of different chromium additions on the microstructure and mechanical properties of multipass weld joint of duplex stainless steel[J]. Metallurgical and Materials Transactions A，2012，43(12)：4678-4687.
[11] ZHU M，XUAN F. Effects of temperature on tensile and impact behavior of dissimilar welds of rotor steels[J]. Materials & Design，2010，31：3346-3352.
[12] WU Q，LU F，CUI H，et al. Role of butter layer in low-cycle fatigue behavior of modified 9Cr and CrMoV dissimilar rotor welded joint[J]. Materials & Design，2014，59：165-175.
[13] WU Q，LU F，CUI H，et al. Microstructure characteristics and temperature-dependent high cycle fatigue behavior of advanced 9% Cr/CrMoV dissimilarly welded joint[J]. Materials Science and Engineering：A，2014，615：98-106.
[14] FARABI N，CHEN D，LI J，et al. Microstructure and mechanical properties of laser welded DP600 steel joints[J]. Materials Science and Engineering：A，2010，527：1215-1222.
