AMP Friction Stir Welding Flash Bainite 4130 ChromeMolybdenum

AMP Friction Stir Welding Flash® Bainite 4130 Chrome-Molybdenum Steel Amber Jerke: Eastern Wyoming College Faculty Advisors: Dr. Michael West, Dr. Bharat Jasthi, Dr. Alfred Boysen SDSM&T Introduction Procedure Flash® Bainite • New development in the 4130 Chrome. Molybdenum steel alloy • “As quenched” state with its microstructure approximately 80% martensite and 20% bainite • Extremely strong and have ductile properties • Developed for armor • Perform trial welds that vary in parameter settings • Obtain metallography and tensile test samples • Evaluate mechanical properties • Ascertain changes to hardness and ductility produced by welding process Results Friction Stir Welding Microhardness Gas Tungsten Arc Welding Microhardness * Note: The red square dotted line represents the average parent metal hardness FSW 3 -1 GTAW 1 -1 550 500 450 400 HV 550 350 300 250 200 0 0, 1 0, 2 0, 3 0, 4 0, 5 0, 6 Distance (inches) 0, 7 0, 8 0, 9 1 0 0, 05 0, 15 FSW 4 -1 550 500 450 400 350 Schematic of Gas Tungsten Arc Welding. Image taken from: http: //www. fabricatingandme talworking. com/2013/08/revis ed-full-color-educationalposters-from-hobart-institute/ 0, 25 0, 3 Distance(Inches) 0, 35 0, 45 0, 5 GTAW 3 -1 550 • Welds were harder in the nugget and softer in the HAZ • Welds had lower strength than the parent metal • With faster travel speeds there is less of a dip in the HAZ (FSW 5 -1 and GTAW 2 -1) • Friction Stir Welding produces better weld quality and complete joint penetration • Gas Tungsten Arc Welding maintained higher hardness on average 350 300 250 200 0 0, 1 0, 2 0, 3 0, 4 0, 5 0, 6 Distance (inches) 0, 7 0, 8 0, 9 1 Future Work 0 0, 1 0, 2 FSW 5 -1 0, 3 Distance (inches) 0, 4 0, 5 • Use filler metal to make a complete fusion weld when welding GTAW • Different types of groove welds used • Optimize parameters • Pull Tensile Test specimens to further assess mechanical properties 0, 6 GTAW 2 -1 550 500 450 400 HV Objective The objective of this project is to evaluate whether it is possible to produce acceptable welds using Friction Stir Welding and to compare the mechanical properties of the weldment of FSW to that of GTAW. Discussions Conclusions HV Gas Tungsten Arc Welding • Traditional welding process where the base metal(s) reach melting point using an electric arc and coalesce Into a weldment. • no flux or slag used to protect the weld metal only shielding gas • Non-consumable tungsten electrode FSW of steel Image taken from: http: //www. megastir. com/? gclid=CIf. Kr. P 72 r 8 CFf. A-Mgod. FQQAJA HV Schematic of Friction Stir Welding Image taken from: http: //hfwebster. com/abouthfw/about-fsw Tensile Test samples from the parent metal. HV Friction Stir Welding • Solid state joining process • Friction builds sending the metal to the plasticizing range • Metal is then stirred together while the tool travels along the joint Sample 4 -1 polished and etched with 2% Nital of FSW for metallography. 350 300 250 200 0 0, 2 0, 4 0, 6 Distance (inches) 0, 8 1 0 0, 05 0, 15 0, 25 0, 3 Distance (inches) 0, 35 0, 45 0, 5 Acknowledgements: This work was made possible by the National Science Foundation REU Back to the Future Site DMR-1157074. Special thanks also to Dr. Alfred Boysen, Dr. Michael West, Dr. Bharat Jasthi, Todd Curtis, and Ian Markon