Properties of Thixocast Spring Steel Ratchets

Abstract:

Forging is state of the art for the production of hand tools in industrial scales. Due to high demands on stiffness and fracture toughness high-strength forged steels are used to provide components with high mechanical load capacity. In spite of all advantages forging is restricted by some means like the freedom of scope. However, because of the extreme thermal load and the hardly avoidable casting defects, hand tools are nowadays not cast. By thixocasting steel technical difficulties can be reduced and new options are provided, which allow manufacturing of components with much higher complexity than forging. During this work ratchets were thixocast successfully using spring steel type 61SiCr7. Based on the STC-concept, a new method to prevent the shot sleeve from damage was tested. Dies made of hot forming tool steel X38CrMoV5 were optimized by simulation and coated by plasma chemical deposition of crystalline Al2O3 protective coatings. The cast parts were heat treated successfully to enhance the toughness, which was measured by tensile and Charpy impact tests.

• Periodical: Solid State Phenomena (Volumes 192-193)
• Pages: 197-203
• DOI: https://doi.org/10.4028/www.scientific.net/SSP.192-193.197
• Online since: October 2012
• Authors: Matthias Bünck, Andreas Bührig-Polaczek
• Keywords: 61SiCr7, Casting, Heat Treatment, Semi-Solid, Steel Thixocasting

References

[1] M.C. Flemings, K.P. Young: Thixocasting of steel, 9th SDCE International Die Casting Exposition an Congress, Paper No. G-T77-092, 1977, pp.1-8.

[2] H. Bramann, C. Afrath, M. Fehlbier, A. Bührig-Polaczek: Casting of cold work steel alloy in semisolid state, Journal of Materials Processing Technology, 2004, pp.155-156.

DOI: 10.1016/j.jmatprotec.2004.04.219

[3] H. Bramann, T. Grimmig, C. Afrath, M. Fehlbier, A. Bührig-Polaczek: Casting of high alloy steels in the mushy state, Steel Research International 75, No 8/9, (2004).

DOI: 10.1002/srin.200405808

[4] G. Hirt, W. Belck, A. Bührig-Polaczek, H. Shimahara, W. Püttgen, C. Afrath: Semi Solid Casting and Forging of Steel, Proceedings of 9th International Conference on Semi-Solid Processing of Alloys and Composites, Pusan, 2006, pp.34-44.

[5] G. Hirt, R. Kopp: Thixoforming – Semi-solid Metal Processing, Wiley-VCH, ISBN: 978-3-527-32204-6, (2009).

[6] M. Bünck, E. Subasic; A. Bührig-Polaczek, K. Jiang, S. Münstermann, J. M. Schneider, K. Fickert, H.J. Günther: Thixocasting combination spanners using stainless steel X39CrMo17. Proceedings of the 11th International Conference on Semi-Solid Processing of Alloy and Composites (Part B), Transactions of Nonferrous Metals Society of China, Beijing, China, Volume 20, ISSN 1003-6326, S. 999-1004 (2010).

DOI: 10.1016/s1003-6326(10)60620-6

[7] M. Bünck, E. Subasic, A. Bührig-Polaczek, K. Jiang, S. Münstermann, J. Schneider, K. Fickert, H. J. Günther: Thixocasting steel hand tools using Al2O3-coated steel and molybdenum dies, Steel Research International, 81, Heft 7, Wiley-VCH, Weinheim, ISSN 1611-3683, S. 581-588 (2010).

DOI: 10.1002/srin.201000032

[8] F. Küthe, C. Afrath, M. Bünck, A. Bührig-Polaczek. Neue Möglichkeiten - Druckgießen von Stählen im teilflüssigen Zustand, 2007, 1+2, pp.48-51.

[9] J.C. Choi, H.J. Park: Microstructural Characteristics of Aluminium 2024 by SIMA Process and Effect of Cold Working, Proceedings of the 5th International Conference of Semi-Solid Processing of Alloys and Composites, 1998, pp.457-464.

[10] O. Kyrylov, D. Kurapov, and J.M. Schneider: Effect of ion irradiation during deposition on the structure of alumina thin films grown by plasma assisted chemical vapour deposition, Applied Physics A 80 (8) (2005) 1657.

DOI: 10.1007/s00339-004-2998-y

[11] K. Jiang, K. Sarakinos, S. Konstantinidis, and J.M. Schneider: Low temperature synthesis of α-Al2O3 films by high-power plasma-assisted chemical vapour deposition, Journal of Physics D: Applied Physics 43 (32) (2010) 325202-1.

DOI: 10.1088/0022-3727/43/32/325202

[12] R. Snyders, K. Jiang, D. Music, S. Konstantinidis, T. Markus, A. Reinholdt, J. Mayer, and J.M. Schneider: Composition-constitution-morphology relationship of Al2O3 thin films deposited by plasma assisted chemical vapor deposition, Surface & Coatings Technology 204 (1/2) (2009).

DOI: 10.1016/j.surfcoat.2009.07.019

[13] D. Apelian. Semi-solid Processing Routes and Microstructure Evolution. Proceedings of the 7th S2P International Conference on Semi-Solid Processing of Alloys and Composites. Tsukuba, Japan : s. n., 2002, S. 25-30.