API TR 938-A : 1996

Executive Summary
For Applications of 11/4 Cr-1/2Mo Steel at 825 deg F
and Higher
Report overview and conclusions
Recommendations for Vessel Fabrication and Repair
   Introduction
   Fabrication Guidelines
   Guideline Details Class 2 Properties
   Class 1 Properties
   Repair Guidelines
Summary of Program and Results of Testing and
Evaluation
   Introduction
   Section A. Literature Review
   Section B. Materials
   Section C. Weld HAZ Transformation Behavior
   Section D. Reheat/PWHT Cracking Assessment
   Section E. Development of Factors to Predict
                Reheat/PWHT Cracking
   Section F. Toughness Evaluations as a Function of
                PWHT
   Section G. Microstructural and Fractographic
                Evaluations
   Section H. Creep Rupture Behavior of the Coarse
                Grained HAZ-Notch Bar and Smooth Bar
                Creep/Stress Rupture Testing
   Section I. Repair Welding Procedures, Behavior of
                Low Carbon Metal and Repaired Weldments
   References
Appendix A - Literature Survey - Cr-Mo Steels - Reheat
and In-Service Cracking
Appendix B - Chemical Composition of 11/4Cr-1/2MoAPI
Materials
Appendix C - Coarse Grained Transformation Behavior and
Associated Microstructures
Appendix D - Assessment of Reheat Cracking Susceptibility
   Appendix D1: Gleeble Simulation Smooth Bar Reheat
   Crack Testing
   Appendix D2: Spiral Notch Testing
   Appendix D3: Development of a New Reheat Cracking
   Test - Preview Test and Evaluation of Reheat
          Cracking in API Materials
Appendix E - Determination of Factors to Quantify Reheat
Cracking Susceptibility Based on Chemical Composition
Appendix F - Toughness Study
Appendix G - Microstructural and Fractographic
Evaluations
   Appendix G1: Fractographic Examination of Notched
   Creep and Gleeble Stress Rupture Samples of API
   Materials
   Appendix G2: SEM Metallographic Investigation and EDS
   Analyses of UT2 and UT3 Materials
   Appendix G3: Phase 1 - High Resolution Electron
   Microscope Evaluation on API Materials
   Appendix G3: Phase II - High Resolution Electron
   Microscope Evaluation on API Materials
   Appendix G4: Transmission Electron Microscope
   Evaluation on API Materials
Appendix H - Creep Rupture Behavior of the Coarse Grained
HAZ
   Appendix H1: Notch Bar and Smooth Bar Creep/Stress
   Rupture Testing
   Appendix H2: Preparation of Extended Length HAZ
   Simulation Specimens by the Gleeble Technique
Appendix I - Repair Welding Procedure
   Behavior of Low Carbon Weld Metal and Repaired
   Weldments
   Temper-Bead Welding Procedure for Repair Welding
Appendix J - Program Tasks

Describes causes and repair of cracking of 1 1/4Cr - 1/2 Mo Steel Equipment early in the operating life.