Lesson 25 IACS Repair Quality Standard for Existing Ships Part II CONTENTS 1. Welding requirement 2. Repair quality standard 3. Doublers on plating 4. Renewal of internals/stiffeners 5. Renewal of internals/stiffeners - transitions inverted angle/bulb profile 1. Welding Requirement A. Correlation of welding consumables with hull structural steels B. C. General requirements to preheating and drying out Dry welding on hull plating below the waterline of vessels afloat Repair quality standard Item Standard Limit Material Grade Same as original or higher Welding Consumables IACS UR-W17 (ref. 6) Approval according. to equivalent international standard Groove / roughness See note and Fig. 22.1 d< Pre-Heating See Table 22.1 Steel temperature not lower than Welding with water on the outside See Section 5.3 Acceptable for normal and high strength steels Alignment As for new construction Weld finish IACS guide for inspection of ship hull welds (ref. 10) NDE IACS guide (ref. 10) NOTE: Slag, grease, loose mill scale, rust and paint, other than primer, to be removed. Remarks See Section 4 At random with extent to be agreed with attending surveyors Grind smooth Moisture to be removed by a heating torch Doublers on plating Doublers on plating Renewal of internals/stiffeners Item Standard Limit Size insert Min. Min. Material grade Same as original or higher Edge Preparation As for new construction. Fillet weld stiffener web/plate to be released over min. d = Welding sequence See fig.22.4 . Weld sequence is 1→ 2 → 3 Alignment As for new construction Weld finish IACS guide for inspection of ship hull welds (ref. 10) NDE IACS guide (ref. 10) Remarks See Section 4. Renewal of internals/stiffeners - transitions inverted angle/bulb profile Termination of straps WORDS Ambient Submerge hydrogen alignment compliance Insert Pitch n. circumferencial throat Internals Transition Taper Strap Asymmetrical adj. adj. 周围环境 v. 浸没 n. 氢 n. 找中、队中 n. 符合 n. 嵌补板 波高 adj. 圆周的 n. 焊喉 n. (pl)内部构件 n. 过渡 v. 逐渐变细/薄 n. 带钢 不对称的 Phrases and Expressions ambient temperature submerged arc welding coated low-hydrogen electrode manual metal arc welding grind smooth weld finish as for new construction at random rounded off corner edge preparation slot welding step welding fillet weld 环境温度 埋弧焊 碱氢焊条 手工电弧焊 研磨平整 焊缝处理 如同新结构(建造) 随机(选择) 倒圆角 (焊接)接边加工 槽焊(长孔焊) 分段焊接 角焊 Assignment 1. Review the text. 2. Do the exercises on Page 249.