The National Shipbuilding Research Program, 1990 Ship Production Symposium, Paper No. 5B-2: Shipboard Aluminum/Steel Welded Transition Joints Evaluation and Improvements
The National Shipbuilding Research Program, 1990 Ship Production Symposium, Paper No. 5B-2: Shipboard Aluminum/Steel Welded Transition Joints Evaluation and Improvements

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Published: 1990

Total Pages: 22

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Aluminum to steel explosion welded transition joints are used to attach aluminum superstructures to steel hulls. Transition joint bond separation sometimes occurs during ship construction. Ingalls Shipbuilding conducted a long term study to determine causes and corrective action for these separations. The aluminum/steel transition joints are manufactured by the explosion bonding process and tested in accordance with MIL-J-24445. Traditional transition joints consist of alloyed aluminum bonded to mild steel with an interlayer of low alloy aluminum. The study reviewed transition joint manufacture and quality testing required by the material specification, reviewed the adequacy of design guidelines and production practices, and considered cost effective methods for corrective action. Modifications in product design and testing, installation design and shipyard production practices can improve reliability. The most important result of this study was development of material with improved Properties. This paper relates the study procedure, findings and recommendations so that transition joint separations can be avoided on future installations. This information is useful for designers and transition joint users.

The National Shipbuilding Research Program, 1991 Ship Production Symposium Proceedings: Paper No. IVB-4. Shipyard Aluminum/Steel Welded Transition Joints
The National Shipbuilding Research Program, 1991 Ship Production Symposium Proceedings: Paper No. IVB-4. Shipyard Aluminum/Steel Welded Transition Joints

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Published: 1991

Total Pages: 10

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Aluminum to steel explosion welded transition joints are used in shipbuilding to attach aluminum superstructures to steel hulls. This paper summarizes long term studies to determine causes of separations and describes actions to prevent separations. The aluminum/steel transition joints are manufactured by the explosion welding process and tested in accordance with MIL-J-24445. Traditional transition joints consist of alloyed aluminum bonded (by the explosion weld) to mild steel with an interlayer of low alloy aluminum. In 1989, production began using an improved transition joint product with the addition of a titanium interlayer between the steel and the low alloy aluminum. Laboratory testing showed the improved product had greater strength and temperature resistance. However, when this product was put into production, disbonding occurred at an alarming rate. As a result, it was discovered that bond notch toughness is a critical property even though it was not required to be measured by MIL-J- 24445. To improve the notch toughness while preserving earlier beneficial improvements, a ductile copper nickel (CUNI) interlayer was added between the steel and the titanium. This paper describes the study results and the development of the latest generation of aluminum steel structural transition.

The National Shipbuilding Research Program. 1992 Ship Production Symposium Proceedings. Paper No. 7C-1: Aluminum Steel Construction in a New 36M (120 Ft) Patrol Boat
The National Shipbuilding Research Program. 1992 Ship Production Symposium Proceedings. Paper No. 7C-1: Aluminum Steel Construction in a New 36M (120 Ft) Patrol Boat

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Published: 1992

Total Pages: 11

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Construction of the U.S. Coast Guard Cutter Leopold, the lead ship of the 36 m (120 ft) Heritage Class, is discussed. A new Structural Critical Aluminum-Steel Transition (SCAST) product, Duratemp II" was selected for the welding transitions between the aluminum deck house and steel deck. The explosion bonded material's higher strength and toughness permitted use of lighter, narrower transition joints (1 cm (0.375") wide x 2 cm (0.75") thick) than are permissible with traditional materials. The unique heat resistance of the material permitted cutting and welding of the small section joints without overheating. The need for corner butt joints was reduced due to the product's reliable bendability. Welding procedures and Quality Assurance procedures are discussed in detail. fabricability, and proven corrosion resistance. This was the first shipboard installation to use this material. The USCG, in cooperation with the manufacturer, chose a 1 cm (0.375") wide x 2 cm (0.75") thick transition joint for use in joining the pilot and deck-house to the steel deck. Fabrication of traditional Aluminum/Steel transition joint materials using bars of this small of a cross-section is generally considered unreliable. Traditional aluminum/steel transition joint products can be significantly degraded if the bond zone is heated above 260 degrees C (500 degrees F) during welding.

The National Shipbuilding Research Program 1985 Ship Production Symposium Volume 2 Paper No. 2: Evaluation of the Usability and Benefits of Twist Wire GMAW and FCAW Narrow Gap Welding
The National Shipbuilding Research Program 1985 Ship Production Symposium Volume 2 Paper No. 2: Evaluation of the Usability and Benefits of Twist Wire GMAW and FCAW Narrow Gap Welding

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Published: 1985

Total Pages: 37

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Puget Sound Naval Shipyard is evaluating and developing the twisted wire narrow gap joints and reduced bevel weld joints for the shipbuilding industry. Test and evaluation work is being accomplished with twisted solid wire and twisted flux cored arc weld on carbon steel, low alloy steels (ASTM-302B) and quenched and temper steels (HY-8O). Weld joint design tolerances, welding parameters tracking systems and weld joint irregularities have been evaluated with both twisted FCAW and solid welding electrodes. All test welds have been accomplished on two and three inch thick base metals. The following elements of the electrode quality were found to be critical for depositing sound metal: uniformity of the twist; tightness of the twist; smoothness of the wire; amounts of residual stress; prevention of looping; and the amount of helix.

The National Shipbuilding Research Program, 1990 Ship Production Symposium, Paper No. 2B-2: Financial Questions -- Industrial Engineering Answers
The National Shipbuilding Research Program, 1990 Ship Production Symposium, Paper No. 2B-2: Financial Questions -- Industrial Engineering Answers

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Published: 1990

Total Pages: 10

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In quest of increased efficiency to make better use of financial resources, industry, both public and private sector, have often been turning to the industrial engineering community for help. And while there has been progress in measuring the efficiency of human resources and establishing work standards, similar efforts in the use of equipment have, in recent years, become of greater interest and will continue to do so in the coming years.

The National Shipbuilding Research Program, 1991 Ship Production Symposium Proceedings: Paper No. IIB-1: Panel Line Developments
The National Shipbuilding Research Program, 1991 Ship Production Symposium Proceedings: Paper No. IIB-1: Panel Line Developments

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Published: 1991

Total Pages: 16

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This paper presents the joint efforts of a research and development project between an American shipyard and an independent engineering company that would resolve issues impacting panel production. The project objectives follow: Develop an efficient means to fit full penetration joints from one side with plates of unequal thickness having the stiffener side up. Develop an efficient one-side welding method for full penetration joints with plates of unequal thickness having the stiffener side up. Develop a flow of material for locating and fitting longitudinal stiffening that would be balanced with the rest of the line. Develop a multi-torch, multi-process longitudinal stiffener welding machine that one person can operate effectively. Develop a method in which transverse stiffening could be fit and welded efficiently with minimal manpower using semi-automatic equipment.

The National Shipbuilding Research Program, 1991 Ship Production Symposium Proceedings: Paper No. IVB-3. Recent MIT Research on Residual Stresses and Distortion in Welded Structures
The National Shipbuilding Research Program, 1991 Ship Production Symposium Proceedings: Paper No. IVB-3. Recent MIT Research on Residual Stresses and Distortion in Welded Structures

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Published: 1991

Total Pages: 19

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This paper presents a summary of recent efforts by the Welding Research Group at the Department of Ocean Engineering, M.I.T. The major thrust of the efforts has been to develop technologies of reducing residual stresses and distortion through in-process control. Part I discusses (a) reduction of longitudinal bending distortion of built-up beams, (b) reduction of radial distortion and residual stresses in girthwelded pipes, (c) reduction of forces acting on tack welds during butt welding, and (d) reduction of residual stresses and distortion in high-strength steel weldments. Part II presents a brief summary of other studies including (e) forming of steel plates by line heating with a high-power laser beam, (f) an intelligent system for flame straightening of panel structures, and (g) a knowledge-based system for minimizing out-of-plane distortion of welded panel structures.

The National Shipbuilding Research Program 1985 Ship Production Symposium Volume 2 Paper No. 16: Computer Optimizing of Bevel Angles for Welded Pipe Joints
The National Shipbuilding Research Program 1985 Ship Production Symposium Volume 2 Paper No. 16: Computer Optimizing of Bevel Angles for Welded Pipe Joints

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Published: 1985

Total Pages: 23

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The most common method for preparing the bevel-angle for welded pipe construction is to keep it at a constant value (say 37 degrees) around the entire periphery of the branch pipe. This paper explores the "optimized bevel-angle" as a function of pipe radii, wall thicknesses, centerline offset, and intersecting angle to keep the resulting weld cross section constant and thus minimize the weld volume while insuring clearance for total weld penetration. The advantages of using the "optimized bevel angle" are demonstrated by computer simulation for pipe diameters from 4-1/2" to 24" for wall thicknesses over the range of O.237" to 1.312". The ratio of the fixed bevel weld volume to the optimized bevel weld volume are shown to range from 1.5 to 5 which implies phenomenal reductions in the attendant welding time.

The National Shipbuilding Research Program, 1990 Ship Production Symposium, Paper No. 2B-1: TQM for Survival
The National Shipbuilding Research Program, 1990 Ship Production Symposium, Paper No. 2B-1: TQM for Survival

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Published: 1990

Total Pages: 12

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Naval shipyards face a declining workload in the nineties and beyond. Survival is a key issue. Total quality management (TQM) is one of the keys to survival. Being the best performer by focusing on customers' ever-demanding needs is the bottom line. Portsmouth Naval Shipyard has developed a TQM effort that will allow us to improve performance, communicate more clearly, and focus on customer demands. Our TQM model requires committed leaders, involves training for everyone, and calls for the building of teams to break down the functional barriers. It includes teams making incremental improvements in all of their work processes and dramatic improvements in the vital few work processes. It also listens to the voice of the customer.