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Commemorative Magazine

IIW International Conference 2012 - Abstracts

aging plants, welding personnel and supervisors should have clear understanding of materials, weld procedures, defective structures and decision making of run/repair/retire as well as post-repair performance of the structures. This presentation will address weld material properties of commonly used structural materials (e.g., P22 and P91 steels) and repair practices employed in components with high failure rates, inlet, exhaust, pressure parts (such as headers, pipes, tubing and tubing attachments), and ancillary components. Life prediction approach based on Failure Assessment Diagram (FAD) will be presented for P22 steel weldment.

dures are recommended. The mechanical properties of the weld metal at ambient temperature are examined and the effects of welding procedural parameters are explored. Creep properties of both undiluted weld metals and crossweld joints are tested and the data are evaluated and compared with those of other 9%Cr-Mo creep resisting steels.

Paper 4: Effective Repair of Industrial Gas Turbine Blades and Vanes Utilizing Welding and Diffusion Brazing
By: Dr. Warren Miglietti, PSM, an Alstom Company, USA Abstract: Modern industrial gas turbine engines have reached over 60% turbine efficiency as a result of many technological advances (component design, materials, coatings, cooling, etc). It is therefore of prime interest to users/owners/operators of these advanced gas turbine engines to have sound component repair capabilities available to support operational and maintenance requirements. Modern engine sets of row 1 and 2 hot section components cost significantly over $1 Million. Processes to Repair these expensive Row 1 and 2 turbine blades and vanes, arguably the highest “frequency of replacement” component in the combustion and hot sections of the turbine, have been developed for over 2 decades now. Welding processes developed for effective component repairs include high frequency gas tungsten arc welding, automated microplasma welding, electron beam welding and laser beam fusion welding and cladding. In some cases these exotic superalloys, utilized in the hot section components are considered “unweldable.” Therefore, processes based on brazing principles such as transient liquid phase bonding and liquid phase diffusion sintering also have been developed for effective component repairs. This paper describes the welding and brazing repair procedures, development and implementation of these technologies. In addition it documents the metallurgical and mechanical characteristics of the repaired regions of the component. Optical and Scanning electron micrographs will be shown to verify the structural integrity of the various weld and braze repair processes utilized, and tensile, stress rupture, low and high cycle fatigue results will also be discussed to further validate the repair. In some cases, the liquid phase diffusion sintering process produced mechanical properties superior to that of their welded counterparts. The mechanical properties of the repair can often approach 90% of the base metals mechanical properties.
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Paper 3: Welding Consumables for Advanced Boron-Cobalt Alloyed 9%Cr-Mo Creep Resisting Steel for Power Generation
By: Dr. Zhuyao Zhang and Graham B. Holloway, Metrode Products Limited, UK Abstract: More than ten years into the 21st century, fossil fuels are currently still the main means of obtaining electric power, and about 65% of electricity consumption worldwide is supplied by fossil fired power plants. It is forecast that this figure will still remain at a level of more than 60% by the year 2030. However, the operation of conventional thermal power plants releases more harmful gases than other power generation technologies. Consequently, finding effective solutions to reduce emissions of harmful gases from thermal power plants has been the major challenge for the power generation industry as well as alloy material developers. In the recent European material programmes COST 522 and COST 536, based on the existing P91 and P92 steels, an advanced 9%Cr-Mo martensitic steel modified with additions of boron and cobalt has been developed. This new alloy has demonstrated promising creep properties. It is hoped that the new steel will deliver creep strength superior to that of P92 so that it will be suitable for applications at higher steam pressures and temperatures. The operating temperature is expected to be at a level up to 625°C-650°C. This presentation introduces the development of the matching welding consumables for the new boron-cobalt alloyed 9%Cr-Mo creep resisting steel. The design of the filler metal composition is discussed and comparison is made with respect to the base alloy additions. The important phase transformation temperatures, such as Ac1, Ms and Mf, of the weld deposits are measured. These critical temperatures are compared with those of P91 and P92 weld metals, and accordingly, suitable welding parameters and post-weld heat treatment (PWHT) proce-

65TH IIW Annual Assembly & International Conference



IIW 2012

Table of Contents for the Digital Edition of IIW 2012

IIW 2012
Contents
Welcome Message
Annual Assembly Location
Colorado
Denver
General Information
IIW 65th Annual Assembly
IIW International Conference 2012 - Program
IIW International Conference 2012 - Abstracts
Speaker Bio Information
Smartphone App
Social Program
Technical Visits
Social Tours
Tour Schedule
Advertising Sponsor Profiles
Commission XIII Fracture Mechanics Seminar
IIW 2012 Sponsors
IIW 2012 - IIW 2012
IIW 2012 - Cover2
IIW 2012 - Contents
IIW 2012 - Welcome Message
IIW 2012 - 3
IIW 2012 - Annual Assembly Location
IIW 2012 - 5
IIW 2012 - Colorado
IIW 2012 - 7
IIW 2012 - Denver
IIW 2012 - 9
IIW 2012 - General Information
IIW 2012 - 11
IIW 2012 - 12
IIW 2012 - IIW 65th Annual Assembly
IIW 2012 - 14
IIW 2012 - 15
IIW 2012 - IIW International Conference 2012 - Program
IIW 2012 - 17
IIW 2012 - 18
IIW 2012 - 19
IIW 2012 - IIW International Conference 2012 - Abstracts
IIW 2012 - 21
IIW 2012 - 22
IIW 2012 - 23
IIW 2012 - 24
IIW 2012 - 25
IIW 2012 - 26
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IIW 2012 - 38
IIW 2012 - Speaker Bio Information
IIW 2012 - 40
IIW 2012 - 41
IIW 2012 - 42
IIW 2012 - 43
IIW 2012 - 44
IIW 2012 - 45
IIW 2012 - 46
IIW 2012 - 47
IIW 2012 - Smartphone App
IIW 2012 - Social Program
IIW 2012 - Technical Visits
IIW 2012 - 51
IIW 2012 - Social Tours
IIW 2012 - 53
IIW 2012 - 54
IIW 2012 - Tour Schedule
IIW 2012 - Advertising Sponsor Profiles
IIW 2012 - 57
IIW 2012 - 58
IIW 2012 - 59
IIW 2012 - 60
IIW 2012 - Commission XIII Fracture Mechanics Seminar
IIW 2012 - IIW 2012 Sponsors
IIW 2012 - 63
IIW 2012 - 64
IIW 2012 - Cover3
IIW 2012 - Cover4
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