9%Ni钢及其在LNG储罐建造中的焊接简

9％Ni钢是含镍量为8．5％～10％Fe—Ni系低碳马氏体型超低温钢，在-196℃具有优异的强韧性，广泛应用于大型液化天然气储罐等低温设备的建造。9％Ni钢通过合理的合金设计、先进的冶炼技术和严格的热处理保证其优异的低温韧性。克服了在大型LNG储罐建造过程中主要出现的孤坑裂纹、横焊打底焊道贯穿裂纹和气孔等焊接缺陷。结合大型LNG储罐工程建设实例，对9％Ni钢及其焊接工艺和焊接工艺评定要点进行归纳分析。

The 9%Ni Steel and Its Weld on the LNG Storage Tank Construction

9% Ni steel, which contains 8.5%- 10% of nickel, is Fe - Ni in low carbon martenslte shape cryogenic steel, with excellent obdurability in -196 ~C, and widely used in the construction of the cryogenic equipment such as liquefied natural gas storage. 9% Ni steel through reasonable alloy design, advanced smelting technology and strict heat treatment guarantee its excellent low temperature toughness. In the process of large LNG storage tank construction main arc crater crack, the crack through backing welding way on horizontal welding, welding defects such as porosity appeared. Combining with an instance of large LNG storage tank construction, make inductive analysis on 9% Ni steel and its welding process and welding procedure qualification points.