North Atlantic ENGINEERING STANDARD SPECIFICATION 1/7 REV. QUALITY SLAG BOWL WELDING AND QUALITY REQUIREMENTS. Approved by.

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1 1/7 Rev Description Revision by Approved by Issue Date YYYY/MM/DD 1 Update from Job KLR 015/04/01 Updated 1.0 and 4.3 PB 016/03/09 KLR 015/04/01 PB 016/03/09 015/04/01 016/03/09 Sud = Sudbury, Ontario, PC = Port Colborne, Thom = Thompson, Manitoba, VB = Voisey s Bay, LH = Long Harbour, Act = Acton, England, Clyd = Clydach, Wales, N/A = Not Applicable

2 /7 1.0 PURPOSE This specification describes the minimum requirements for welded repairs of slag bowls performed offsite by third parties..0 APPLICATION This specification applies to slag bowls used by Transportation at the Copper Cliff Smelter. 3.0 REFERENCE DOCUMENTATION The following documents were used in the development of this document or have instructions and procedures applicable to it. They shall be used in their most recent revision. ASME V CGSB CSA W47.1 CSA W59 CSA W178. ISO 971 Non-Destructive Evaluation Non-Destructive Testing Qualification and certification of personnel Certification of Companies for Fusion Welding of Steel Welded Steel Construction Certification of Welding Inspectors Non-destructive testing -- Qualification and certification of NDT personnel 4.0 REQUIREMENTS 4.1 GENERAL The contractor / vendor / supplier shall have access to and be knowledgeable regarding all applicable standards relating to their scope of services. 4. EXAMINATIONS Non-Destructive examiners shall be certified by Natural Resources Canada in accordance CGSB All personnel performing interpretation shall, at minimum, hold a level II in the type of non-destructive examination being performed. Certification with the International Certification to ISO 971 level II or III in the appropriate method(s) is also acceptable. Weld visual inspectors shall have a working knowledge of ASME V, CSA W59 acceptance criteria.

3 3/7 4.3 MANUFACTURER QUALIFICATIONS Manufacturers and their welding subcontractors shall be registered with the Canadian Welding Bureau in accordance with CSA W47.1 (Certification of Companies for Fusion Welding of Structural Steel latest edition), Division 1 or. The supplier shall ensure that a copy of the ISO Certificate of Registration and pertinent welding manuals have been received by Vale (Quality Assurance Group, Specialty Engineering). The Contractor s Quality Manual shall be available to audit by Vale, at any time during the repair process. 4.4 MANAGEMENT OF CHANGE A detailed management of change process shall be included in the ISO quality management program. This process shall describe which changes require revisions of stamped design drawings. 4.5 CRACK REPAIRS BY EXCAVATION AND FILLING Small washouts, gouges, and cracks not protruding through bowl or covering less than one square foot can be repaired by grinding and welding. Methodology is as follows: a. Grind out crack to sound metal b. Utilize MT to verify sound metal c. Preheat repair area and 6 surround to 350 F, verifying with temperature gun. d. Weld stringer beads using 7018 electrode. e. Monitor interpass temperature. It shall be maintained between 350 F and 450 F. f. Peen weld beads in 1 max layers with an air gun to relieve stresses using considerable care. The intent is to use just enough force applied along the weld centerline to move the metal, but not rupture it. Peening shall be completed while the deposited surface is still red hot. g. Long crack weld beads shall be laid down using either block or cascade sequence. These are demonstrated in CSA W59 Figures E.14B and E.14C, respectively. h. Post weld heat treat to 350 F for 5 hours in order to diffuse hydrogen from weld. i. Perform MT on final weld

4 4/7 4.6 CRACK REPAIRS BY WELDING USING BACKING STRIP Small washouts, gouges, and cracks protruding through bowl or covering less than one square foot can be repaired by welding using a backing strip. Methodology is as follows: a. Grind out crack through bowl, ensuring width of excavation is minimum ¼ thick, and area is covering less than one square foot. b. Utilize MT to verify sound metal c. Prep area such that each side is beveled to degrees, similar to joint E.5C- of CSA W59. d. Fit ¼ thick ASTM A516 grade 70 backing plate, such that ½ distance is between weld prep and edge of backing plate, all around. e. Preheat repair area and 6 surround to 350 F, verifying with temperature gun. f. Tack weld backing plate using 7018 electrode, ensuring no tack is within ½ of edge of joint. g. Weld stringer beads using 7018 electrode using split layer technique. Long crack weld beads shall be laid down using either block or cascade sequence. These are demonstrated in CSA W59 Figures E.14B and E.14C, respectively. h. Monitor interpass temperature. It shall be maintained between 350 F and 450 F. j. Peen weld beads in 1 max layers with an air gun to relieve stresses using considerable care. The intent is to use just enough force applied along the weld centerline to move the metal, but not rupture it. Peening shall be completed while the deposited surface is still red hot. i. Post weld heat treat to 350 F for 5 hours in order to diffuse hydrogen from weld. j. Perform MT on final weld 4.7 REPAIRS USING INSERT PATCH All defects protruding through bowl, or covering more than one square foot shall be repaired using the patch method. Methodology is as follows: a. Cut out hole in slag bowl around center of defect. b. Patch plate dimension shall be sized such that there is a 1 to 1½ surrounding the defect, and rounded 6 at the corners. c. Patch plate material shall be ASTM A516 grade 70 with impact of 0 ft lbs at - F or CSA G WT Cat 3 impacts. d. Fit up patch plate and prep weld area so that /3 of welding will occur on outside and 1/3 of welding occurs on inside. The joint can be prepped as double bevel with min 30 degrees or double J groove. e. Preheat repair area and 6 surround to 350 F, verifying with temperature gun.

5 5/7 f. Weld patch from outside and GTSM wherever possible using 7018 electrode. g. Monitor interpass temperature. It shall be maintained between 350 F and 450 F. k. Peen weld beads in 1 max layers with an air gun to relieve stresses using considerable care. The intent is to use just enough force applied along the weld centerline to move the metal, but not rupture it. Peening shall be completed while the deposited surface is still red hot. h. Perform MT on weld final weld inside and out. i. Perform stress relieving by: i. Inserting in oven at 600 F and heat to 1150 F at a rate of 100 F / hour ii. Hold for thickness 4.5 hrs iii. Cool to 600 F in furnace at rate of 100 F / hour iv. Remove from furnace and cool in still air until room temperature 4.8 DOCUMENTATION TO VALE Upon completion to repair, prior to delivery, the following documentation shall be forwarded to Transportation Contact: - Materials Test Certificates (MTRs) for plates used for patchwork - NDE reports - Welding Procedures - Consumable Data Sheets - Heat Treatment Charts / Certificates - Map of weld repair on Slag Bowl Defect Monitoring Chart (Appendix C) - Signed off non-conformances Mill test, confirmation of qualifications of all welding operators and other pertinent quality documents shall be retained by the manufacturer for a period of five years from the date of delivery and made available to Vale upon request. All documentation and correspondence shall include the Vale purchase order number, and the slag bowl number 5.0 APPENDICES Appendix A: Revision and Transition Notes Appendix B: Keywords Appendix C: Slag Bowl Defect Monitoring Chart

6 6/7 Appendix A: Revision and Transition Notes (Revisions are listed in reverse chronological order with the most recent revision at the top. Revision notes describe: what was changed, why it was changed, and the plan to implement the change, including whether changes are retroactive) Note: The revision notes are a summary of the changes and may not necessarily be a complete list. Revision Revised scope to apply exclusively to offsite repairs performed by third parties and removed requirement to upload certificates in Quadrem. Revision 1 New spec updated from job to define three types of repairs: 1. crack repairs by excavation & filling,. crack repairs by welding using backing strip 3. repairs using insert patch. Slag Bowl, Welding, Patch, Crack, CSA W59 Appendix B: Keywords

7 7/7 Appendix C: Slag Bowl Monitoring Defect Chart TRANSPORTATION DEPARTMENT SLAGBOWL DEFECT MONITORING CHART SLAGBOWL No. xxxx DEFECT No. STATUS TYPE DESCRIPTION (LENGTH,WIDTH DIA.) 6.0 DATE 06/15/99 08/15/99 11/15/99 1 REPAIRED DEC13/99 CRACK IN ELEPHANT SKIN 8 long 1/8 wide 1 long 1/8 wide 1 long 1/4 wide 1 LEFT RIGH TOP 1