To Study the Mechanical Properties of AISI H11 Tool Steel after Heat Treatment

Harvinder Singh¹ , Aneesh Goyal² , Rajdeep Singh³

Section:Research Paper, Product Type: Isroset-Journal
Vol.5 , Issue.1 , pp.9-14, Jan-2019

Online published on Jan 31, 2019

Copyright © Harvinder Singh, Aneesh Goyal, Rajdeep Singh . This is an open access article distributed under the Creative Commons Attribution License, which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited.
 

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Abstract :
Belonging to the class of chromium tool steels, AISI H11 possesses very good toughness and hardness, and is therefore suitable for hot metalforming jobs performed at very high loads. Mostly used in fabrication of helicopter rotor blades, H11 also has great potential as a die steel in hot-work forging and extrusion. This alloy steel can be heat treated to increase the service life and dimensional accuracy of the die and tooling. Main aim of the current investigation was to formulate an optimum heat treatment strategy for H11 steel, especially for hot work applications. High-speed milling and electric discharge machining were used to fabricate samples for tensile and impact testing. After various types of heat treatment (annealing, austenitizing, air cooling or oil quenching, single and double tempering), these samples were tested for hardness, toughness (impact), yield strength, tensile strength, and ductility. Microstructural analysis was also performed to analyze the effect of heat treatment on mechanical properties. As tempering temperature increases, hardness initially increases and then starts to gradually decrease; impact strength first decreases and then increases; and yield strength exhibits a fluctuating pattern of initial decline followed by an increase and another decrease. Even though H11 steel is highly suitable for both hot and cold-work, it is surprisingly not a common choice for metalworking dies and tools. Results presented here can encourage die designers and hot-work practitioners to explore the versatility of this tool steel, and to adopt appropriate heat treatment strategies for different applications.

Key-Words / Index Term :
H11 tool steel, hardness, toughness, tensile properties, optimum heat treatment, microstructure

References :
[1] Kaszynski J, Breitler R (2002), How the Steelmaking Process Influences the Properties of Hot Work Die Steels, Technical Paper - Society of Manufacturing Engineers, Issue CM02-216, p 1-12
[2]ASM International (1990), ASM Handbook Volume 1: Properties and Selection  Nonferrous Alloys and Special Purpose Materials, 10th edition, American Society for Metals, Metals Park, Ohio
[3]Davis JR (ed) (1995), ASM Specialty Handbook: Tool Materials, ASM International, Materials Park, Ohio
[4] Roberts GA, Krauss G, Kennedy R (1998), Tool Steels, 5th edition, American Society for Metals, Metals Park, Ohio
[5]Szumera J (2003), The Tool Steel Guide, Industrial Press, New York
[6] Bryson WE (2005), Heat Treatment, Selection, and Application of Tool Steels, 2nd edition, Hanser Gardner Publications, Cincinati
[7] Fnides B, Yallese MA, Aouici H (2008), Hard Turning of Hot Work Steel AISI H11: Evaluation of Cutting Pressures, Resulting Force and Temperature, Mechanika, 72 (4), p 59-63
[8] Klobčar Da , Tušek Ja, Taljat Bb (2008), Thermal Fatigue of Materials for Die-Casting Tooling, Materials Science and Engineering A, 472 (1-2), p 198-207
[9]Cornacchia G, Gelfi M, Faccoli M, Roberti R (2008), Influence of Aging on Microstructure and Toughness of Die-Casting Die Steels, International Journal of Microstructure and Materials Properties, 3 (2-3), p 195-205
[10] Pellizzari M, Zadra M, Molinari A (2007), Tribological Properties of Surface Engineered Hot Work Tool Steel for Aluminum Extrusion Dies, Surface Engineering, 23 (3), p 165-168
[11] Barrau Oa, Boher Ca, Gras Rb, Rezai-Aria Fa (2003), Analysis of the Friction and Wear Behavior of Hot Work Tool Steel for Forging, Wear, 255 (7-12), p 1444-1454
[12] Nolan D, Leskovsek V, Jenko M (2006), Estimation of Fracture Toughness of Nitride Compound Layers on Tool Steel by Application of Vickers Indentation Method, Surface and Coating Technology, vol. 201, p 182-188
[13] Totten GE (ed) (2007), Steel Heat Treatment Handbook; Vol 1: Metallurgy and Technologies; Vol 2: Equipment and Process Design, 2nd edition, CRC Press, Boca Raton
[14] ASM International (1991), ASM Handbook Volume 4: Heat Treating, American Society for Metals, Metals Park, Ohio
[15] ASTM E18 (2008), Standard Test Method for Rockwell Hardness of Metallic Materials, American Society of Testing and Materials
[16] ASTM E23 (2007), Standard Test Method for Notched Bar Impact Testing of Metallic Materials, American Society of Testing and Materials
[17] ASTM E8 (2008), Standard Test Method for Tension Testing of Metallic Materials, American Society of Testing and Materials
[18] Qamar SZ, Sheikh AK, Arif AFM (2008), A CVN-KIC Correlation for H13 Tool Steels, International Journal of Materials and Product Technology (IJMPT), 33 (4), p 421-432
[19] Qamar SZ, Sheikh AK, Arif AFM, Pervez T (2006), Regression-Based CVN-KIC Models for Hot Work Tool Steels, Materials Science and Engineering A, 430 (1-2), August 2006, p 208-215
[20] Arif AFM, Sheikh AK, Qamar SZ and al-Fuhaid KM (2003), A Study of Die Failure Mechanisms in Aluminum Extrusion, Journal of Materials Processing Technology, 134 (3), March 2003, p 318-328