液化天然气储罐9%Ni钢板超声检测问题探讨

Discussion on Ultrasonic Detection of 9%Ni Steel Plate for LNG Inner Tank

液化天然气(简称LNG)全容储罐由混凝土外罐与金属内罐组成,内罐是直接储存LNG的设备,决定着整个储罐的安全与稳定性,作为内罐关键材料的9%Ni钢板,其内部质量直接影响钢板的结构性能。基于国内某LNG项目,从9%Ni钢板超声检测标准、检测方式、合格级别及流程进行了论述,同时对于检测时机的选择及5 mm薄板检测条件、缺陷的识别及判定进行了分析,以排除风险,确保出厂钢板满足技术要求。

The liquefied natural gas(LNG for short)storage tank consists of the concrete outer tank and metal inner tank,the inner tank is the equipment that directly stores LNG,it determines the safety and stability of the entire storage tank.The internal quality of the9%Ni steel plate,as the key material for inner tank,directly affects the structural performance of the steel plate.In this paper,based on a domestic LNG project,the ultrasonic detection standard,detection method,qualification level and process of the9%Ni steel plate were described.In addition,the selection of detection time,conditions of detection for5mm thick plate,the identification and determination of the defect were analyzed,in order to eliminate risk and ensure that the steel plate delivered meets the technical requirements.