See discussions, stats, and author profiles for this publication at: https://www.researchgate.net/publication/291969993 Team DragonSlayer Extreme C70: Materials Design (Final Presentation) Presentation · June 2004 DOI: 10.13140/RG.2.1.1704.0401 CITATIONS READS 0 65 4 authors , including: Kittichai Sojiphan Julian Benz King Mongkut's University of Technology North Bangkok Colorado School of Mines 76 PUBLICATIONS 36 CITATIONS 7 PUBLICATIONS 67 CITATIONS SEE PROFILE SEE PROFILE Some of the authors of this publication are also working on these related projects: Metallurgical Simulation of Rail Steel During Thermite Welding Using SYSWELD View project Microstructure Evolution Study of Railway Steel Subjected to Thermite Welding View project All content following this page was uploaded by Kittichai Sojiphan on 26 January 2016. The user has requested enhancement of the downloaded file.
Dragonslayer Extreme C70 MSC 390 Materials Design Dragon Slayer Extreme C70 Julian Benz Ethan-Young Chang Akbar Naqvi Kittichai Sojiphan June 5, 2004 1
Dragonslayer Extreme C70 Agenda 1. Need/Background/Inspiration/Passion 2. Property Objectives 3. System Structure 4. Design Approach 5. Preliminary Results/Final Result 6. Conclusion 7. Future Work June 5, 2004 2
Dragonslayer Extreme C70 Our Inspiration Martin Zeit June 5, 2004 3
Dragonslayer Extreme C70 The Dragonslayer Design Project History • design sword capable of battling dragons for QuesTek Innovations LLC • must meet aesthetic and technical requirements: – accurate design of sword – retain hardness in extreme heat – resist corrosive dragon’s blood – pierce through dragon’s armored scales June 5, 2004 4
Dragonslayer Extreme C70 The Dragonslayer history (continued) • Sword needs to be marketable Be able to cut through Japanese samurai katana increase value of collectors item • Expand to use in real world • Focus on high cost specialized applications June 5, 2004 5
Dragonslayer Extreme C70 Why need ultra-high hardness steels? • Superior fatigue/wear resistance • Higher contact stresses Strength • Weight reduction (~50% in gears) Toughness – Decrease strain on engine – Cut pollution and operating costs June 5, 2004 6
Dragonslayer Extreme C70 Other Applications • Tool and die industry • Recycling blades for polymeric material shredding (e.g. automobile tires) use of dragonslayer alloy would increase life of blades • EDC research on other applications: – Golf clubs – Bike locks June 5, 2004 7
Dragonslayer Extreme C70 Need/Background Existing secondary hardening carburized steels Co Ni Cr Mo V C (core) C (case) Ferrium C69-M3B 19.6 2.57 4.9 2.11 0.1 0.071 0.6-0.7 Ferrium C69-1 28 3.1 5.1 2.5 0.02 0.1 0.7 June 5, 2004 8
Dragonslayer Extreme C70 Property Objective C69-1 C69-M3B C70 Case Hardness 1000 VHN 890 VHN 1076 VHN Core Hardness 435 VHN 388 VHN <435 VHN 150 o C 157 o C >~50 o C M s Temp (case) 463.55 o C 482.2 o C >300 o C M s Temp (core) 1050 o C 1050 o C <1100 o C T s Temp (case) M 2 C DF (case) 29.76 kJ/mol 25.88 kJ/mol MAX (~29.76 kJ/mol) Sigma DF (core) 6.34679 kJ/mol 2.7661 kJ/mol MIN (~2.7661 kJ/mol) K-Lee 4.53e-28 2.37e-26 ~4.53e-28 482 o C (16hr) 550 o C (1hr) ~500 o C Tempering T June 5, 2004 9
Dragonslayer Extreme C70 Property Objective – CES Result Core Case June 5, 2004 10
Dragonslayer Extreme C70 Property Objective – CES Analysis • No material currently available that completely satisfies our property objective • High-alloys steels were materials that came closest to meeting the either the case or core properties • Osmium appeared to be a potential candidate CES database not reliable June 5, 2004 11
Dragonslayer Extreme C70 System Structure June 5, 2004 12
Dragonslayer Extreme C70 System Structure – Cryogenic Treatment • Existence of retained austenite due to low M s temperature • Alloy subjected to cryogenic treatment using liquid N 2 (T = 77K) Transformation of retained austenite to martensite (reduction of up to 97%*) Increase in hardness! *http://www.carbotecheng.com/cryostudy2.html#Overviewm June 5, 2004 13
Dragonslayer Extreme C70 System Structure June 5, 2004 14
Dragonslayer Extreme C70 System Structure – Shot Peening Regular Shot Peening Laser Shot Peening • 3 Effects – Primary Effect: Induction of residual compressive layer – Secondary Effect: Reduction in the level of retained austenite and refining of microstructure – Ternary Effect: Roughening of the surface (adverse!) June 5, 2004 15
Dragonslayer Extreme C70 System Structure – Shot Peening 3 Types Available 1. Single Shot Peening 2. Double Shot Peening 3. Laser Shot Peening June 5, 2004 16
Dragonslayer Extreme C70 System Structure – Shot Peening • Single Shot Peening – Applied after cryogenic treatment, not simultaneously – Primary objective is to convert the remaining retained austenite to martensite June 5, 2004 17
Dragonslayer Extreme C70 System Structure June 5, 2004 18
Dragonslayer Extreme C70 System Structure – Shot Peening • Double Shot Peening – Applied after tempering – Primary objective apply residual compressive layer – Secondary objective convert any remaining or newly formed retained austenite to martensite (this will be explained in detail in tempering section) June 5, 2004 19
Dragonslayer Extreme C70 System Structure – Shot Peening • Laser Shot Peening – Applied in alternative to single/double shot peening – Objective same as regular shot peening, but able to provide enhanced results • Smoother surface • Deeper penetration through utilization of shock wave • Possible to increase hardness by almost 10%* • If applicable in our design, an increase in hardness by almost 5% expected – High cost! June 5, 2004 20 *I. Yakimets et al., Wear , 256, 311 (2004)
Dragonslayer Extreme C70 System Structure June 5, 2004 21
Dragonslayer Extreme C70 System Structure – Tempering • Designed to be between 450~550 o C • Need to accommodate both M 2 C and sigma phase driving force – T 1 / M 2 C driving force – T 1/ sigma phase driving force • Consider A s temperature (~350 o C) – Effective M s temperature higher due to shot peening – Any converted austenite after tempering converted to martensite by shot peening June 5, 2004 22
Dragonslayer Extreme C70 System Structure – Grinding/Polishing • Adverse effect of shot peening roughening of the surface – Increase surface friction – Act as stress concentration points • Lightly ground or polish to obtain smooth surface (~ m < 1mm carburized case) June 5, 2004 23
Dragonslayer Extreme C70 Design Approach Carbon Content (Case, Core) Strengthening Model M concentration Stoichiometry for case Tempering Temperature for M 2 C Coarsening Rate Strengthening Ni, Co content Ms Temperature Minimize Sigma Phase Driving Vary Ni, Co along constant Ni, Co determined Force, Maximize M 2 C Driving Force case Ms line Vary Cr, Mo, V along M determined stoichiometric line Solution Temperature Calculate Core Carbon Content Co-Ni-Cr-Mo-V- C(case) -C(Core) Check M s Temperature June 5, 2004 24
Dragonslayer Extreme C70 Strengthening Model Total Hardness: • Solid Solution strengthening • Precipitation Strengthening • Shear Mechanism (d<d*) • Orowan Looping Mechanism (d>d*) • Dislocation Strengthening • Martensitic Structure Strength 65 VHN 1100VHN 0.8wt%C (case) June 5, 2004 25
Dragonslayer Extreme C70 Calibration of Strengthening Model @ V/V f =0.8 GS=65VHN C69-1 (1010VHN @482 o C,16hr) C69-M3B (890VHN @550 o C,1hr) R~19 Angstrom R~20 Angstrom R~19.5 Angstrom June 5, 2004 26
Dragonslayer Extreme C70 Design Approach Carbon Content (Case, Core) Strengthening Model Stoichiometry for case M concentration Tempering Temperature for M 2 C Coarsening Rate Strengthening Ni, Co content Ms Temperature Minimize Sigma Phase Driving Vary Ni, Co along constant Ni, Co determined Force, Maximize M 2 C Driving Force case Ms line Vary Cr, Mo, V along M determined stoichiometric line Solution Temperature Calculate Core Carbon Content Co-Ni- Cr-Mo-V-C(case) -C(Core) Check M s Temperature June 5, 2004 27
Dragonslayer Extreme C70 M concentration (M 2 C stoichiometry) [X(Cr)+X(Mo)+X(V)-2*X(C)=0] • 0.8wt%C (case) • wt.%-19.6Co-2.57Ni (C69-M3B) • Temp = 1100 o C June 5, 2004 28
Dragonslayer Extreme C70 Design Approach Carbon Content (Case, Core) Strengthening Model M concentration Stoichiometry for case Tempering Temperature Coarsening Rate for M 2 C Strengthening Ni, Co content Ms Temperature Minimize Sigma Phase Driving Vary Ni, Co along constant Ni, Co determined Force, Maximize M 2 C Driving Force case Ms line Vary Cr, Mo, V along M determined stoichiometric line Solution Temperature Calculate Core Carbon Content Co-Ni-Cr-Mo-V- C(case) -C(Core) Check M s Temperature June 5, 2004 29
Dragonslayer Extreme C70 Coarsening rate Reference: C69-1 coasening rate @ 482C: 4.5e-28 s/(m 2 (J/mol)) June 5, 2004 30
Dragonslayer Extreme C70 Tempering Temperature Reference: C69 coarsening rate @ 482C: 4.5e-28 s/(m 2 (J/mol)) A2a A2b A2c A2d A2e 478~480 o C, Tempering Temperature: 479 o C June 5, 2004 31
Recommend
More recommend
