本规范涵盖了海洋结构物焊接结构中使用的两个等级的高强度钢板，其选定的关键部分必须抵抗冲击、塑性疲劳载荷和层状撕裂。50级覆盖厚度不超过6英寸。（150毫米）包括在内，60级覆盖厚度不超过4英寸。（100毫米）包括在内。

This specification covers two grades of high strength steel plate for use in welded construction of offshore structures, in selected critical portions which must resist impact, plastic fatigue loading, and lamellar tearing. Grade 50 is covered in thicknesses up to 6 in. (150 mm) inclusive, and Grade 60 is covered in thicknesses up to 4 in. (100 mm) inclusive.