308 Prakt. Met. Sonderband 38 (2006)
high proportions of retained austenite. This austenite, which will be partially or fully
transformed into upper plus lower bainite during tempering depending on the degree of
alloying, shall affect the resulting toughness. Likewise, the controlled addition of alpha
forming elements should be taken care of, since they accelerate the kinetics of the
formation of ferrite, which, on nucleating from coarse austenitic grains, could favor the
formation of the unfavourable Widmanststten variety.
The quenchabilities of poleshoes “A” and “B” are very similar. However, given their
thickness, it will not be possible to avoid the formation within their nucleus of a bainite-
martensitic structure during oil quenching. Therefore, a double normalizing is advisable
prior to quenching in agitated oil, followed by tempering.
REFERENCES
[1] Stahlschlissel (“key to steel”), 19 Edition, VDI Verlag, 2001.
[2] Malcom blair.: “Steel Castings”, Properties and Selection: Irons, Steels, and High-
Perfomance Alloy, Metals Handbook, Volume 1, Tenth Edition, ASM International.
Materials Park, OH (USA), 1990, pp. 367-369, 372-37.
[3] Vander Voort G. F.: Metallography. Principles and Practice. Materials Sciencie and
Engineering Series. McGraw Hill, (USA), 1984.
[4] Pero-Sanz Elorz, J.A.: Ciencia e Ingenieria de Materiales, CIE, Dossat 2000, Madrid
(Espafia), 2000.
[5] Asensio Lozano, Juan.: “Apuntes de Metalografia”, 6° Curso de la especialidad de
Metalurgia en la Escuela Superior de Ingenieros de Minas de Oviedo, 1998.
[6] Apraiz, J.: “Influencia de los factores en el temple de los aceros (Chapter VI)’,
“Templabilidad (Chapter VII)”, “Revenido (Chapter IX)”, Tratamientos térmicos de los
aceros, CIE, Dossat 2000, Madrid (Espafia), 2000.
[7] http.//lengm01.ms.ornl.gov/TTTCCTPIots.html
[8] Steel Castings Handbook, Sixth Edition, “Hardenability and Heat Treatment’, Steel
Founders’ Society of America and ASM International, 1995, pp. 24.2 - 24.42.
[91 A.M. Mikhailov: “Steel Casting (Chapter 10)”, Metal Casting, Mir Publishers Moscow,
1987, pp.192-213.
Table I.Composition range for the GS 35CrMoV 10 4 Quality in accordance with DIN
Standard No. 17755, and chemical analyses of the poleshoes
sm ee
% weight Industrial piece Laboratory samples G$ 35 CrMoV 10 4
5 a JQ i%4 A B ! DIN 1.7755
; ‘0.456 0.887 0.353 0.355 0.376 0.32 — 0.39
Mn 0.722 0.827 0.75 0.835 0.753 0.6 — 1.0
0.629 0.606 0.544 0.62 0.56 <0.6
0.003 0.013 0.006 0.017 0.007 <0.015
: 0.014 0.016 0.013 0.018 0.014 <0.020
‘u 0.023 0.075 0.02 0.07 0.021 —
r 2.286 2.303 2.016 2.35 2.072 22-27
i 0.03 0.047 0.036 0.047 0.036 wenn
Al total 0.06 0.027 0.072 0.025 0.047 ween
Al soluble 0.051 0.0151 0.0476 0.017 0.039 ween
v 0.145 0.147 0.125 0.14 0.12 0.05 — 0.15
ri 0.001 0.001 0.003 0.001 0.002 ween
Mo 0.446 0.434 0.294 0.42 0.28 03-05
1 00145 0.01 0.0176 nN 0.01 —