February 2022 Volume 4

FORGING RESEARCH

Effect of Processing on the Microstructure-Performance Comparison between a 4340 Wrought Steel and a 4340 Selective Laser Melted (SLM) Steel Progress Report V (Final Stage 6) Forging Industry Education Research Foundation September 31st, 2021 Pedro de Souza Ciacco, Luis Fellipe Simoes, Jackeline Vicente Vazquez, Javier Carreno Saavedra and Prof. Dr. C. Isaac Garcia Ferrous Physical Metallurgy Group Department of Mechanical Engineering and Materials Science – MEMS, University of Pittsburgh

3.2. Microstructural Comparison and Calculations .......... 20 3.2.1. XRDMeasurements ......................................... 23 3.2.2. Hardness Measurements .................................. 25 3.2.3. Crystallographic Texture .................................. 26 3.3. Mechanical Properties . ............................................... 28 3.3.1. Mechanical Properties Evaluation and Comparison ............................................................... 28 3.3.2.1. Tensile Testing . ...................................... 28 3.3.2.2. Impact Charpy Testing .......................... 29 3.3.2.2.1. Fractography Comparison ............. 30 4. Milestones Accomplished ................................................. 30 5.Conclusions . ...................................................................... 31 6. Acknowledgements ........................................................... 31 7. References .......................................................................... 31 APPENDIX A .......................................................................34 APPENDIX B ....................................................................... 38

Table of Contents 1. Executive Summary............................................................. 2 2. Experimental Procedure ..................................................... 3 2.1. Materials and Processing ............................................... 3 2.2. Laboratory Hot Rolling ................................................ 3 2.3. Microstructural Analysis . ............................................. 5 3. Results and Discussion . ...................................................... 7 3.1. Microstructural and Advanced Microstructural Analysis . .................................................... 7 3.1.1. Overview –Thermomechanical Processing 1 (TMP 1) ......................................................................... 7 3.1.2. Thermomechanical Processing 2 (TMP 2) ......... 11 3.1.2.1. Hot Rolled + Water Quenched (HR + WQ) Condition ............................................................. 12 3.1.2.2. Hot Rolled +Water Quenched + Tempering at 1150°F (621°C) . .................................................... 14 3.1.2.2.1. Tempering at 1150°F (621°C) at a faster Heating Rate .................................................. 15 3.1.2.2.2. Tempering at 1150°F (621°C) at a slower Heating Rate .................................................. 18

FIA MAGAZINE | FEBRUARY 2022 84