AÇOS FERRAMENTA PARA TRABALHO A QUENTE COM BAIXO TEOR DE SILÍCIO: CARACTERIZAÇÃO E APLICAÇÕES
LOW SILICON HOT WORK TOOL STEELS: CHARACTERIZATION AND APPLICATIONS
Mesquita, Rafael Agnelli; Barbosa, Celso Antonio; Gonçalves, Cristiane Sales; Kestenbach, Hans-Jurgen
http://dx.doi.org/10.4322/tmm.00404002
Tecnol. Metal. Mater., vol.4, n4, p.7-15, 2008
Resumo
Os aços ferramenta para trabalho a quente são empregados como matrizes para conformação de metais em alta temperatura. Recentemente, novos aços ferramenta, com menor teor de silício, têm sido utilizados, gerando substancial melhoria de desempenho das matrizes. O presente trabalho discute resultados da caracterização mecânica e microestrutural de tais aços, também apresentando algumas análises de casos. As propriedades mecânicas foram avaliadas quanto à dureza e tenacidade em impacto, em função da temperatura de revenimento. Para caracterização microestrutural, foi utilizada a técnica de microscopia eletrônica de transmissão, com o objetivo de caracterizar os carbonetos secundários, os principais responsáveis pelo endurecimento dos materiais. São observadas diferenças significativas dos carbonetos secundários em função do teor de silício, estando relacionadas, diretamente, às propriedades mecânicas avaliadas. A redução do teor de silício diminui a presença de carbonetos finos e agulhados; isto pode explicar a menor tenacidade dos aços ferramenta de alto teor de silício, sendo proposto um possível mecanismo. Desta forma, os resultados mecânicos e microestruturais justificam o aumento de desempenho desta nova classe de aços ferramenta para trabalho a quente, com menor teor de silício.
Palavras-chave
Aço-ferramenta, Silício, Tenacidade, Desempenho.
Abstract
Hot work tool steels are mainly used as dies for hot forming processes. New grades have been recently developed, with lower silicon content, leading to a substantial performance increase. The present paper describes the mechanical properties and microstructural characterization of such hot work steels, as well as case studies. Hardness and toughness were determined for a wide range of tempering temperatures; concerning microstructural characterization, transmission electron microcopy was used for observing secondary carbides – the main responsible for the hot strength of these steels. Important differences were observed on the secondary carbides, which are considered responsible for the differences on the mechanical properties. The reduction in silicon content reduces the amount of fine needle shaped carbides; this can explain the lower toughness of high silicon content grades and a possible mechanism is proposed. Therefore, the microstructural and mechanical results enable the understanding of the higher performance of this new class of hot work tool steels, with lower silicon content.
Keywords
Tool steel, Phosphorus, Silicon, Toughness
Referências
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13 MESQUITA, R.A.; BARBOSA, C.A. Efeito do Si e P na tenacidade do aço H11, utilizado em ferramentas de trabalho a quente. In: CONGRESSO ANUAL DA ABM, 61., 2006, São Paulo. Anais... São Paulo: Associação Brasileira de Metalurgia e Materiais, 2006. 1 CD ROM
14 MESQUITA, R.A.; BARBOSA, C.A. Aços ferramenta de alto desempenho para matrizes de fundição sob pressão. Metalurgia & Materiais, v. 59, n. 539, p. 17-22, Nov. 2003
15 SCHMIDT, M. L. Effect of austenitizing temperature on laboratory treated and large section sizes of H-13 tool steel. In: KRAUSS, G.; NORDBERG, H. Tool materials for moulds and dies. Illinois, EUA: Colorado School of Mines, 1987. p. 118-64
16 BANERJEE, B.R. Embrittlement of high-strength tempered alloy martensites. Journal of the Iron and Steel Institute, v. 203, Part 2, p. 166-74, Feb. 1965
17 SONDEREGGER, B.; KOZESCHNIK, E.; BISCHOF, M.; LEITNER, H.; CLEMENS, H.; SVOBODA, J.; FISCHER, F.D. Characterization and simulation of precipitation kinetics during heat treatment of the hot-work tool steel X38CrMoV 5-3. In: CONFERENCE ON TOOLING: Tooling materials and their applications from research to market. 7., 2006, Turin, Italy. Proceedings... Turin: Politecnico di Torino, 2006. v. 1, p. 533-40
18 LEITNER, H.; CLEMENS, Characterization of namometer-sized precipitates in tool steels. In: CONFERENCE ON TOOLING: Tooling materials and their applications from research to market. 7., 2006, Turin, Italy. Proceedings... Turin: Politecnico di Torino, V. 1, May 2006, p. 695-706
19 GARRISON Jr, W.M.A comparion of the effects of cobalt, silicon, nickel and aluminum on the tempering response of a medium chromium secondary hardening steel. Journal of the Iron and Steel Institute, v. 46, n. 5, p. 782-4, May 2006
20 OKUNO, T. Effect of microstructure on the toughness of hot work tool steels, AISI H13, H10 and H19. Journal of the Iron and Steel Institute, v. 27, n.1, p.51-59. Jan. 1987
21 THELMING, K-E. Steel and Is Heat Treatment. 2. ed, London: Butterwroth, 1984
22 OLEFJORD, I. Temper embrittlement. International Metals Reviews, v. 23, n. 4, p.149-163, 1978
23 GUTTMANN, M.; DUMOULIN, P.; WAYMAN, M. The thermodynamics of interactive co-segregation of phosphorus and alloying elements in iron and temper-brittle steels. Metallurgical Transactions A, v. 13A, n.10, p. 1693-711, Oct. 1982
24 BRIANT, C.L.; BANERJI, S.K. Intergranular failure in steel: the role of grain boundary composition. International Metals Reviews, v.23, n. 4, p.164-199, Apr. 1978. ZAHUMENSKY, P; JANOVEC, J; BLACH, J. Some aspects of tempered martensite embrittlement in 3Cr-Mo-V steel. ISIJ International, v. 34, n. 6, p. 536-40, 1994
25 SARIKAYA, M; JHINGAN, A.K.; THOMAS, G. Retained austenite and tempered martensite embrittlement in mediumcarbon steels. Metallurgical Transactions A. v.14A, n. 6, p. 1121-33, June 1983
26 THOMAS, G. Retained austenite and tempered martensite embrittlement. Metallurgical Transaction A, v. 9A, n. 3, p. 439-50, Mar. 1978
27 BRIANT, C.L. Role of carbides in tempered martensite embrittlement. Materials Science and Technology, v. 5, n. 2, p. 138-47, Feb. 1989
28 BRIANT, C L; BANERJI, S K. Tempered martensite embrittlement and intergranular fracture in an ultra-high-strength sulfur-doped steel. Metallurgical Transactions A, v. 12A, n. 2, p. 309-19, Feb. 1981
29 YU, J.; McMAHON JR, C.J. The effects of composition and carbide precipitation on temper embrittlement of 2.25 Cr-1 Mo Steel: Part 2. Effects of Mn and Si. Metallurgical Transactions A, v. 11A, n. 2, p. 291-300, Feb. 1980
30 ZIA-EBRAHIMI, F; KRAUSS, G. Mechanisms of tempered martensite embrittlement in medium-carbon steels. Acta Metallurgica et Materialia, v. 32, n. 10, p. 1767-77, Oct. 1984
31 ALTSTETTER, C.J.; COHEN, M.; AVERBACH, L. Effect of silicon on the tempering of AISI 43XX steels. Transactions of the ASM, v. 55, n.1, p. 287-300, 1962
32 OWEN, S. The effect of silicon on the kinetics of tempering. Transactions of the ASM, v. 46, p. 812-829, 1954
33 WANG, R.; ANDRÉN, H.-O., Wisel, H.; DUNLOP, G.L. The role of alloy composition in the precipitation behaviour of high speed steels. Acta Metallurgica et Materialia, v. 40, n. 7, p. 1727-38, July 1992.
2 MESQUITA, R. A.; FRANÇA, L. C.; BARBOSA, C. A. Análise de casos e aplicações dos aços TENAX 300 e VHSUPER. Tecnologia em Metalurgia e Materiais, v. 2, n.1, p.70-5, jul./set. 2005
3 SCHRUFF, I. Comparison of properties and characteristics of hot-work tool steels X 38 CrMoV 5 1 (Thyrotherm 2343), X 40 CrMoV 5 1 (Thyrotherm 2344), X 32 CrMoV 3 3 (Thyrotherm 2365) and X 38 CrMoV 5 3 (Thyrotherm 2367). Thyssen Edelstahlwerke Technische Berichte. Special Issue, p. 32-44, May 1990
4 GRELLIER, A.; SIAUT, M. A new hot work tool steel for high temperature and high stress service conditions.; In: INTERNATIONAL CONFERENCE ON TOOLING, 6., 2002, Karlstad, Suécia. Proceedings… Karlstad: Karlstad University, 2002. p. 33-41
5 SANDBERG, O.; KLARENFJORD, B.; LINDOW, H. A new hot work tool steel with improved properties. In: INTERNATIONAL CONFERENCE ON TOOLING, 5., 1999, Leoben, Austria. Proceedings… Austria: Institut für Metallkunde und Werkstoffprüfung, 1999. p. 601-10
6 FUCHS, K.-D. Hot-work tool steels with improved properties for die casting applications. In: INTERNATIONAL CONFERENCE ON TOOLING, 6., 2002, Karlstad, Suécia. Proceedings... Karlstad: Karlstad University, 2002. p. 15-22
7 MESQUITA, R.A.; FRANÇA, L.C.; BARBOSA, C.. Desenvolvimento de um novo aço ferramenta para trabalho a quente com tenacidade otimizada. In: CONGRESSO ANUAL DA ABM, 57., 2002, São Paulo. Anais... São Paulo: Associação Brasileira de Metalurgia e Materiais, 2002. p. 444-53. 1 CD ROM
8 MESQUITA, R.A.; BARBOSA, C.A. Desenvolvimento de um novo aço ferramenta com superior resistência a quente. In: CONGRESSO ANUAL DA ABM, 60., 2005, Belo Horizonte. Anais... São Paulo: Associação Brasileira de Metalurgia e Materiais, 2005. p. 27-37. 1 CD ROM
9 GARRISON JR, W.M. Influence of silicon on strength and toughness of 5wt-%Cr secondary hardening steel. Materials Science and Technology, v. 3, n. 4, p. 256-9, April 1987
10 DELAGNES, D.; LAMESLE, P.; MATHON, M.H.; MEBARKI, N.; LEVAILLANT, C. Influence of silicon content on the precipitation of secondary carbides and fatigue properties of a 5% Cr tempered martensitic steel. Materials Science & Engineering A, v. 394, n.1-2, p. 435-44, 2005
11 UMINO, M.; SERA, T.; KONDO, K.; OKADA, Y.; TUBAKINO, H. Effect of silicon content on tempered hardness, high temperature strength and toughness of hot working tool steels. Tetsu-to-Hagane, v. 89, n. 6, p. 673-9, June 2003
12 ULE, B.; VODOPIVEC, F.; PRISTAVEC, M.; GRESOVNIK, F. Temper embrittlement of hot work die steel. Materials Science and Technology, v. 6, n. 12, p. 1181-5, Dec. 1990
13 MESQUITA, R.A.; BARBOSA, C.A. Efeito do Si e P na tenacidade do aço H11, utilizado em ferramentas de trabalho a quente. In: CONGRESSO ANUAL DA ABM, 61., 2006, São Paulo. Anais... São Paulo: Associação Brasileira de Metalurgia e Materiais, 2006. 1 CD ROM
14 MESQUITA, R.A.; BARBOSA, C.A. Aços ferramenta de alto desempenho para matrizes de fundição sob pressão. Metalurgia & Materiais, v. 59, n. 539, p. 17-22, Nov. 2003
15 SCHMIDT, M. L. Effect of austenitizing temperature on laboratory treated and large section sizes of H-13 tool steel. In: KRAUSS, G.; NORDBERG, H. Tool materials for moulds and dies. Illinois, EUA: Colorado School of Mines, 1987. p. 118-64
16 BANERJEE, B.R. Embrittlement of high-strength tempered alloy martensites. Journal of the Iron and Steel Institute, v. 203, Part 2, p. 166-74, Feb. 1965
17 SONDEREGGER, B.; KOZESCHNIK, E.; BISCHOF, M.; LEITNER, H.; CLEMENS, H.; SVOBODA, J.; FISCHER, F.D. Characterization and simulation of precipitation kinetics during heat treatment of the hot-work tool steel X38CrMoV 5-3. In: CONFERENCE ON TOOLING: Tooling materials and their applications from research to market. 7., 2006, Turin, Italy. Proceedings... Turin: Politecnico di Torino, 2006. v. 1, p. 533-40
18 LEITNER, H.; CLEMENS, Characterization of namometer-sized precipitates in tool steels. In: CONFERENCE ON TOOLING: Tooling materials and their applications from research to market. 7., 2006, Turin, Italy. Proceedings... Turin: Politecnico di Torino, V. 1, May 2006, p. 695-706
19 GARRISON Jr, W.M.A comparion of the effects of cobalt, silicon, nickel and aluminum on the tempering response of a medium chromium secondary hardening steel. Journal of the Iron and Steel Institute, v. 46, n. 5, p. 782-4, May 2006
20 OKUNO, T. Effect of microstructure on the toughness of hot work tool steels, AISI H13, H10 and H19. Journal of the Iron and Steel Institute, v. 27, n.1, p.51-59. Jan. 1987
21 THELMING, K-E. Steel and Is Heat Treatment. 2. ed, London: Butterwroth, 1984
22 OLEFJORD, I. Temper embrittlement. International Metals Reviews, v. 23, n. 4, p.149-163, 1978
23 GUTTMANN, M.; DUMOULIN, P.; WAYMAN, M. The thermodynamics of interactive co-segregation of phosphorus and alloying elements in iron and temper-brittle steels. Metallurgical Transactions A, v. 13A, n.10, p. 1693-711, Oct. 1982
24 BRIANT, C.L.; BANERJI, S.K. Intergranular failure in steel: the role of grain boundary composition. International Metals Reviews, v.23, n. 4, p.164-199, Apr. 1978. ZAHUMENSKY, P; JANOVEC, J; BLACH, J. Some aspects of tempered martensite embrittlement in 3Cr-Mo-V steel. ISIJ International, v. 34, n. 6, p. 536-40, 1994
25 SARIKAYA, M; JHINGAN, A.K.; THOMAS, G. Retained austenite and tempered martensite embrittlement in mediumcarbon steels. Metallurgical Transactions A. v.14A, n. 6, p. 1121-33, June 1983
26 THOMAS, G. Retained austenite and tempered martensite embrittlement. Metallurgical Transaction A, v. 9A, n. 3, p. 439-50, Mar. 1978
27 BRIANT, C.L. Role of carbides in tempered martensite embrittlement. Materials Science and Technology, v. 5, n. 2, p. 138-47, Feb. 1989
28 BRIANT, C L; BANERJI, S K. Tempered martensite embrittlement and intergranular fracture in an ultra-high-strength sulfur-doped steel. Metallurgical Transactions A, v. 12A, n. 2, p. 309-19, Feb. 1981
29 YU, J.; McMAHON JR, C.J. The effects of composition and carbide precipitation on temper embrittlement of 2.25 Cr-1 Mo Steel: Part 2. Effects of Mn and Si. Metallurgical Transactions A, v. 11A, n. 2, p. 291-300, Feb. 1980
30 ZIA-EBRAHIMI, F; KRAUSS, G. Mechanisms of tempered martensite embrittlement in medium-carbon steels. Acta Metallurgica et Materialia, v. 32, n. 10, p. 1767-77, Oct. 1984
31 ALTSTETTER, C.J.; COHEN, M.; AVERBACH, L. Effect of silicon on the tempering of AISI 43XX steels. Transactions of the ASM, v. 55, n.1, p. 287-300, 1962
32 OWEN, S. The effect of silicon on the kinetics of tempering. Transactions of the ASM, v. 46, p. 812-829, 1954
33 WANG, R.; ANDRÉN, H.-O., Wisel, H.; DUNLOP, G.L. The role of alloy composition in the precipitation behaviour of high speed steels. Acta Metallurgica et Materialia, v. 40, n. 7, p. 1727-38, July 1992.