目前，国内已建成投产的导管架平台主结构均使用355MPa级的高强度钢。为减重以满足下水驳船的施工能力，某在建深水导管架使用超过2万吨420MPa级超高强度钢，且将实现国产化。为确保导管架的建造安全，本文通过常规化学成分分析和厚度方向拉伸试验，同时采用焊接方法Z向窗型层状撕裂试验评定该深水导管架用国产超高强度钢Z向API 2Y-60厚板的层状撕裂性能和敏感性。试验结果表明，国产API 2Y-60钢厚度方向的性能良好，层状撕裂敏感性低，具备在导管架节点使用的基本条件。本研究结果保障了导管架平台安全，可为类似结构钢的首次应用论证提供参考。

All main structure of jacket platforms that have been built and put into operation in China use high strength steel of 355MPa at present. In order to reduce weight to meet the capacity of launching barge， some deepwater jacket under constrcution uses more than 20000t extra-high strength steel of 420MPa， which is produced in domestic. To ensure the securely construction of the jacket， the lamellar tearing performance and susceptibility of domestic extra-high strength steel API 2Y-60 for deepwater jacket are evaluated in this paper through chemical composition analysis， Z-direction tensile test and Z-type window test. The test results mean that the domestic API 2Y-60 steel has good lamellar tearing resistance， which is the basic condition of steels used in jacket tubular joints. The research results can ensure the safety of jacket platform， and also provide a reference for the first application demonstration of similar structural steel.