1. Lesson 25 IACS Repair Quality Standard for Existing Ships Part II

2. 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

3. 1. Welding Requirement A. Correlation of welding consumables with hull structural steels B. General requirements to preheating and drying out C. Dry welding on hull plating below the waterline of vessels afloat

4. Repair quality standard ItemStandardLimitRemarks Material GradeSame as original or higherSee Section 4 Welding ConsumablesIACS UR-W17 (ref. 6)Approval according. to equivalent international standard Groove / roughnessSee note and Fig. 22.1d <Grind smooth Pre-HeatingSee Table 22.1Steel temperature not lower than Welding with water on the outsideSee Section 5.3Acceptable for normal and high strength steels Moisture to be removed by a heating torch AlignmentAs for new construction Weld finishIACS guide for inspection of ship hull welds (ref. 10) NDEIACS guide (ref. 10)At random with extent to be agreed with attending surveyors NOTE: Slag, grease, loose mill scale, rust and paint, other than primer, to be removed.

5. Doublers on plating

7. Renewal of internals/stiffeners

8. ItemStandardLimitRemarks Size insertMin. Material gradeSame as original or higherSee Section 4. Edge PreparationAs for new construction. Fillet weld stiffener web/plate to be released over min. d = Welding sequenceSee fig.22.4. Weld sequence is 1→ 2 → 3 AlignmentAs for new construction Weld finishIACS guide for inspection of ship hull welds (ref. 10) NDEIACS guide (ref. 10)

9. Renewal of internals/stiffeners - transitions inverted angle/bulb profile

10. Termination of straps

11. WORDS  Ambientadj. 周围环境  Submergev. 浸没  hydrogen n. 氢  alignment n. 找中、队中  compliance n. 符合  Insertn. 嵌补板  Pitchn. 波高  circumferencial adj. 圆周的  throat n. 焊喉  Internalsn.(pl) 内部构件  Transitionn. 过渡  Taperv. 逐渐变细 / 薄  Strapn. 带钢  Asymmetricaladj. 不对称的

12. Phrases and Expressions  ambient temperature 环境温度  submerged arc welding 埋弧焊  coated low-hydrogen electrode 碱氢焊条  manual metal arc welding 手工电弧焊  grind smooth 研磨平整  weld finish 焊缝处理  as for new construction 如同新结构（建造）  at random 随机（选择）  rounded off corner 倒圆角  edge preparation( 焊接 ) 接边加工  slot welding 槽焊 ( 长孔焊 )  step welding 分段焊接  fillet weld 角焊

13. Assignment  1. Review the text.  2. Do the exercises on Page 249.