materials technology research activities · materials technology research activities faculty of...
TRANSCRIPT
Materials Technology Research Activities Faculty of Engineering, Universidad Panamericana, Mexico City, Mexico
Roberto González Ojeda, PhD, [email protected] María José Quintana, PhD, [email protected]
Universidad Panamericana, Campus México Tel. (52-55) 5482 1600 Ext. 5258
Research activities in Materials Science and Technology at the Engineering Labs of U.P. Mexico City are
focused on the characterization and analysis of metallic materials (steels and aluminum alloys) and the
simulation of the behavior of mechanical systems using finite element software. The research is carried out by
María José Quintana, Ph.D., and Roberto González, Ph.D. along with master and undergraduate engineering
students, mainly from the mechanical and mechatronics programs.
Strong collaboration with the SID-MET-MAT group at the University of Oviedo (School of Mines), Spain, has
allowed the research to impact in industrial technology applications.
October 2014
Publications o Machinability improvement through heat treatment in 8620 low carbon alloyed steel
o CARACTERIZACIÓN MECÁNICO-MICROSTRUCTURAL DEL ACERO INOXIDABLE 304 A TEMPERATURA ELEVADA
o Ultrafine grained HSLA steels for cold forming
o The nodal wear model (NWM) as an alternative to understand the mechanisms of flow and wear in the blast furnace
crucible
o PROPIEDADES MECÁNICAS DE ACEROS DE FASE DUAL DE GRANO ULTRAFINO
o EFECTIVIDAD DE LA REFRIGERACIÓN EN EL DISEÑO DE HORNOS
o VENTAJAS E INCONVENIENTES DE LA INCORPORACIÓN DE ÓXIDOS DE TITANIO EN LA CARGA DE UN ALTO
HORNO
o Ultrafine grained steels and the n coefficient of strain hardening
o Dual phase ultrafine grained steels produced by controlled rolling processes
o Mechanism knowledge of the flow and wear in the blast furnace crucible with the nodal wear model
o Protection Mechanisms for Blast Furnace Crucible Using Titanium Oxides
o Superplastic HSLA steels: Deformation and Failure
o Superplasticity of Ultrafine Grained Low-Carbon HSLA
o Spark plasma sintering of tungsten carbide powders using metallic and ceramic additions
o Superplasticity of ultrafine grained low-alloy steels
o Cooling efficiency in furnace design
o Structural ultrafine grained steels obtained by advanced controlled rolling
o Superplastic HSLA steels:microstructure and failure
o Microstructural Changes of a Construction Steel Caused by Hot Deformation
o Mechanical behaviour of thermomechanically produced ultrafine grained dual-phase steels
o Tribo-corrosion protection of valves and rotors using cermet layers applied with HVOF
o Effect of Pressure in the Microstructure of Die Cast Al-8.5Si-3.5Cu Alloys
Laboratory Facilities at Universidad Panamericana
Book: Refractory and Ceramic Materials
Publications
Machinability improvement through heat treatment in 8620 low carbon alloyed steel L.F.Verdeja, J.I.Verdeja and R. González, “Machinability improvement through heat treatment in 8620 low carbon alloyed steel”, Machining Science and Technology, 2009, 13, pp. 529-542.
The effect of different heat treatments is evaluated on SAE 8620 low-carbon alloyed steel by means of drilling tests.
Improving machinability through prior heat treatment in steels used for nitro-carburizing surface treatments is very
important in the manufacturing of large series of parts, due to its impact in production costs. This is the case for the
commonly used SAE 8620 grade, in its carburized and quenched and tempered state, for the production of gears, shafts and
other transmission box components for the automobile industry. The machinability of the steel, determined by simple drilling
tests (which are typical in industry labs), is a function of microstructure, which is determined by the state in which the steel
is received and/or heat treatments prior to carburizing. This work shows that by employing some inter-critic annealing
treatments, followed by sub-critic isothermal ones, the machinability of 8620 steel can be improved by ∼16% over the
typical as-received cold drawn state.
CARACTERIZACIÓN MECÁNICO-MICROSTRUCTURAL DEL ACERO INOXIDABLE 304 A TEMPERATURA
ELEVADA María José Quintana Hernández, Roberto González Ojeda, Alfredo González Ruiz “CARACTERIZACIÓN MECÁNICO-MICROSTRUCTURAL DEL ACERO INOXIDABLE 304 A TEMPERATURA ELEVADA”, MEMORIAS DEL XV CONGRESO INTERNACIONAL ANUAL DE LA SOMIM, 23 al 25 DE SEPTIEMBRE, 2009 CD. OBREGÓN, SONORA. MÉXICO.
The use of stainless steel at very high temperatures requires a detailed study of stress-strain and
microstructure relationships. The tests made with a 304 type steel are presented in order to study tensile
properties at both 700 and 850C, as well as microstructure characteristic such as austenite grain size
(predominant phase in this steel), twinning and carbide M23C6 precipitates distribution and size, comparing
them also to room temperature data. Though the resistance is reduced in considerable amount, the results
indicate that the time the samples are maintained at the test temperature is a critical factor in the stress-strain
curve, which is related to the presence of twins and its different concentration at the core or exterior part of
the sample, as well as the amount of carbide precipitates at the interior or boundaries of the austenite crystals.
http://www.somim.org.mx/
Ultrafine grained HSLA steels for cold forming R.González, J.O.García, M.A.Barbés, M.J.Quintana, L.F.Verdeja, J.I.Verdeja, “Ultrafine grained HSLA steels for cold forming”, Journal of Iron and Steel Research, International, 2010, 17(10), pp. 50-56.
The industrial level production of ultrafine grained (or ultrafine ferrite) ferrous alloys was investigated through
three examples of steels that complied with the EN 10149-2 Euronorm and were produced by advanced
controlled hot rolling techniques. The steel samples were tension tested and chemically analyzed, and the
microstructure was evaluated through quantitative metallographic techniques to determine parameters such as
yield stress, amount of microalloying elements, strain hardening coefficient, grain size, and grain size
distribution. These steels were microalloyed with Ti, Nb, and Mn with ASTM grain sizes of approximately 13-
15. The careful control of chemical composition and deformation during production, giving a specific attention
to the deformation sequences, austenite non-recrystallization temperatures and allotropic transformations
during cooling, are indispensable to obtain steels with an adequate strain hardening coefficient that allows cold
working operations such as bending, stretching or drawing.
The nodal wear model (NWM) as an alternative to understand the mechanisms of flow and wear in the blast
furnace crucible R.González, M.A.Barbés, L.F.Verdeja, I.Ruiz Bustina, J.Mochón, R.M.Duarte, M.Karbowniczek, “The nodal wear model (NWM) as an alternative to understand the mechanisms of flow and wear in the blast furnace crucible”, Archives of Metallurgy and Materials, 2010, 55, 4, pp. 1113-1123.
The presence of thermocouples in the lining of crucibles has become a general practice in the new construction
of blast furnaces. The Nodal Wear Model (NWM) has also emerged as an instrument that, while using
experimental data, obtains nodal variables whose experimental measurement is not possible: global coefficient
of pig-iron/refractory heat transfer hpig�iron/lining g� and nodal temperature Ti. Starting from these nodal
properties, the wear of the lining or the growth of scabs may be controlled, independently of the mechanisms
responsible for them. In the same way, the properties and influence zone of the dead man in the hearth of the
blast furnace may be calculated, along with those regions where the fluid is allowed to move without any other
restrictions than the ones of the corresponding viscous flow (raceway hearth region).
PROPIEDADES MECÁNICAS DE ACEROS DE FASE DUAL DE GRANO ULTRAFINO Quintana Hernández María José, González Ojeda Roberto, Verdeja González Luis Felipe, Verdeja González José Ignacio. “PROPIEDADES MECÁNICAS DE ACEROS DE FASE DUAL DE GRANO ULTRAFINO”, MEMORIAS DEL XVI CONGRESO INTERNACIONAL ANUAL DE LA SOMIM, 22 al 24 DE SEPTIEMBRE, 2010 MONTERREY, NUEVO LEÓN, MÉXICO.
Double-phase steels are an excellent alternative in the production of automotive parts that require high
mechanical resistance, high impact strength and elevated elongation. These materials are produced based in
low-alloy steels reducing costs and resulting in a combination of martensite and ferrite structures with ultrafine
grained sizes. These characteristics are accomplished through a strict control of rolling conditions: strain rate,
cooling rate and direct quenching. This work presents the results of tension testing of two types of double
phased steels, along with microstructural characterization before and after testing.
http://www.somim.org.mx/
EFECTIVIDAD DE LA REFRIGERACIÓN EN EL DISEÑO DE HORNOS R. Colás; I. Ruiz; M.F. Barbés; E. Marinas; M.A. Barbés; R.González, “EFECTIVIDAD DE LA REFRIGERACIÓN EN EL DISEÑO DE HORNOS”, Congreso y Exposición del Acero CONAC 2010, Monterrey, N.L. México. Sesión de Posters.
During fusion, reduction or thermal treatment of a steel charge, adding chemical or electrical energy is
necessary to guarantee the process viability. Under these circumstances, it will be reasonable to design the
lining of the furnaces in such a way that heat loss through the walls were minimal. Nevertheless, it may be
demonstrated, that in some situations removing the maximum amount of heat from the walls is more efficient
than forcing an exhaustive thermal insulation in them. The work presents advices about design of both walls
and cooling systems in furnaces, obtained when quantitatively analyzing the temperatures at specific places
through the nodal wear model.
http://conac.aistmexico.org.mx/en/about-conac/conac-2014
VENTAJAS E INCONVENIENTES DE LA INCORPORACIÓN DE ÓXIDOS DE TITANIO EN LA CARGA DE UN
ALTO HORNO J. Mochón(1), M.J. Quintana, A. Alfonso; E. Marinas; M.A. Barbés; L.F. Verdeja, “VENTAJAS E INCONVENIENTES DE LA INCORPORACIÓN DE ÓXIDOS DE TITANIO EN LA CARGA DE UN ALTO HORNO”, Congreso y Exposición del Acero CONAC 2010, Monterrey, N.L. México. Sesión de Posters.
The prolongation of the working campaign of a blast furnace in modern steelmaking practices, has been linked
to the crucible life. Addition of titanium oxide has been a frequent practice during operation in an attempt to
protect the crucible walls, independently of physical or chemical characteristics, which results from a operation
point of view, in both advantages and disadvantages. The work proposes incorporation of rutile (TiO2) and
ELECTRODES
GAS OUTLET
SECURITY
VALVES
TEMPERATURE
SENSORS
STEEL SHEET
COOLING (WATER)
MONOLITHIC
REFRACTORY
illmenite (FeO•TiO2) in the refractory matrix of the lining, as a practice that results in the protection of the
crucible without disturbing the operation of the blast furnace.
http://conac.aistmexico.org.mx/en/about-conac/conac-2014
Ultrafine grained steels and the n coefficient of strain hardening R.González,M.J.Quintana, L.F.Verdeja,J.I.Verdeja,”Ultrafine grained steels and the n coefficient of strain hardening”, Memoria de trabajos de difusión científica y técnica , 2011, n. 9, pp. 45-54. (no idexada)
Though many efforts have been made to obtain ultrafine grained steels, the industrial production level has not
yet been reached due to the plastic instability during forming. The present work shows, using three examples,
that high strength low alloy steels produced by advanced thermomechanical controlled rolling are in fact
ultrafine grained steels with grain sizes below 5 µm, establishing also a connection between the coefficient of
strain hardening, mechanical strength and admissible thickness tolerances in steel sheets, in order to use these
materials in cold work forming (bending and drawing). A minimum value of coefficient n must be reached in
order to assure commercial use of the steel sheet.
Dual phase ultrafine grained steels produced by controlled rolling processes M.J.Quintana, R.González, L.F.Verdeja, J.I.Verdeja, “Dual phase ultrafine grained steels produced by controlled rolling processes”, MS&T11, Oct. 16-20 2011, Ohio, USA, Recent developments in steel processes, pp. 504-511
Double-phase steels are an excellent alternative in the production of automotive parts that require high
mechanical resistance, high impact strength and elevated elongation. These materials are produced using low-
alloy steels as a basis, reducing costs and resulting in a combination of martensite and ferrite structures with
ultrafine grain sizes. These characteristics are accomplished through a strict control of rolling conditions: strain
rate, cooling rate and direct quenching. This work presents the results of tension testing of two types of double
phased steels, along with microstructural characterization, in order to understand the effect of the advanced
thermomechanical controlled rolling processes on the formation of the microstructure and the resulting
mechanical properties.
PASO - I
ESCORIA
REFRACTARIO
DE CARBON U
OXÍDICO (TAZA
CERÁMICA)
Proceso de Reducción-Precipitación del
Carburo de Titanio, TiC, en la intercara
del refractario con el arrabio
Zona con menor resistencia
al transporte de calor
1-iT
2-iT
Figura 2. Mecanismo de protección de cualquier calidad refractaria en zonas desgastadas a través de
la precipitación de carburo de titanio, TiC, en compuestos cerámicos laminados.
Zona/Lámina con
elevada concentración
de TiO 2
Zona/Lámina conelevada concentración
de TiO 2
ARRABIO
Mechanism knowledge of the flow and wear in the blast furnace crucible with the nodal wear model González R., Barbés M.A., Verdeja l.F., Ruiz-Bautista I., Mochón J., Duarte M.R., Karbowniczek M., Migas P., “Mechanism knowledge of the flow and wear in the blast furnace crucible with the nodal wear model”, Metallurgy and Foundry Engineering, 2011, vol. 37 n. 2, pp. 123-132. (no idexada)
Protection Mechanisms for Blast Furnace Crucible Using Titanium Oxides Javier Mochón, Maria Jose Quintana, Iñigo Ruiz-Bustinza, Roberto González Ojeda, Erika Marinas Garcia, Miguel Ángel Barbés Fernández, Luis Felipe Verdeja González, “Protection Mechanisms for Blast Furnace Crucible Using Titanium Oxides”, Metallurgical and Materials Engineering, 2012, vol. 18, n. 3, pp. 195-201.
In modern steelmaking the duration of a working campaign for a blast furnace is related to the life of the
crucible. Adding titanium oxide has been a frequent practice in the operation routines for modern blast
furnaces, seeking the protection of the crucible walls, independently from its physical or chemical
characteristics. These practices, as conventional operation of iron and steelmaking installations, present both
advantages as well as undesirable consequences. The work proposes the incorporation of rutile (TiO2) or
illmenite (FeO·TiO2) in the refractory matrix of the linings, as a practice that results in a protection of the
crucible without altering, under any circumstance, the regular operation of the installation.
Superplastic HSLA steels: Deformation and Failure S. Fernandez, M.J. Quintana, R.Gonzalez, J.I. Verdeja, “Superplastic HSLA steels: Deformation and Failure”, Microscopy & Microanalysis 2012, July 29-August 2 2012, Phoenix, USA, Failure Analysis of Structural Materials.
Superplasticity of Ultrafine Grained Low-Carbon HSLA J.I. Verdeja, M.J. Quintana, J.O. Garcia, L.F. Verdeja, R. Gonzalez, S. Fernandez, “Superplasticity of Ultrafine Grained Low-Carbon HSLA”, MS&T12, Oct. 7-11 2012, Pittsburgh, PA, USA, Recent Developments in Steel Processing, pp. 945-956
Steels with ultrafine grained structure may present superplastic behavior at specific temperatures and strain
rates that allow the grain boundary sliding mechanisms to be activated. The work presents high temperature
tension tests in a low carbon, low alloy steel obtained by advanced thermomechanical controlled rolling
processes, showing at 800°C elongations as high as 200%. The microstructure of the steel was analyzed in
order to identify ferrite and pearlite grain boundaries, and their interaction after the specimens were deformed,
showing intergranular decohesions, restored ferrite grains and elimination of banded structure, which are
evidence of superplastic mechanisms in this material which is, in fact, ultrafine grained as demonstrated by
quantitative metallographic techniques and grain size distribution analysis
Spark plasma sintering of tungsten carbide powders using metallic and ceramic additions M.J.Quintana, J.I.Verdeja, R.Gonzalez and L.F.Verdeja, “Spark plasma sintering of tungsten carbide powders using metallic and ceramic additions”, Innovative Manufacturing Technology 2, Ed. Piotr Rusek, Krakow, Poland, 2012, p. 335-343.
Spark Plasma Sintering (SPS) allows the densification of powder-based materials by applying both temperature
and axial pressure in very short time periods. The work presents experimental results on different tungsten
carbide (WC) powders used to manufacture insert tools, or tungsten carbide composites with metallic (Ti, Cu,
Ni) or ceramic (alumina) additions, in order to understand the densification phenomena. The condition for
tungsten carbide-based hard materials to perform as tool inserts, is to have very high density and not to
decompose the original WC powders while forming a liquid phase that allows densification. SEM micrographs
and X-ray diffraction analysis were performed to observe the phase behavior during SPS.
Superplasticity of ultrafine grained low-alloy steels S.Fernandez, M.J.Quintana, J.O.Garcia, L.F.Verdeja, R.Gonzalez and J.I.Verdeja, “Superplasticity of ultrafine grained low-alloy steels”, Memoria de Trabajos de Difusión Científica y Técnica, No 10, 2012, p. 45-56.
Steels with ultrafine grained structure may present superplastic behavior at specific temperatures and strain
rates that allow the grain boundary sliding mechanisms to be activated. The superplastic behavior implies
deformation to large strains by grain-boundary sliding with diffusional accommodation, as described by the
Ashby-Verrall model. The work presents high temperature tension tests in a low carbon, low alloy steel
obtained by advanced thermomechanical controlled rolling processes, showing at 800°C elongations as high as
200%. The microstructure of the steel was analyzed in order to identify ferrite and pearlite grain boundaries,
and their interaction after the specimens were deformed. Microanalytical techniques (Optical and SEM) show
evidence of: damage growth that prevents the development of higher elongations to failure, non-uniform flow
(relative movement-rotation of grains in close proximity to each other) and intergranular non-superplastic
deformation (quasi-uniform flow); thus leading to premature failure.
Cooling efficiency in furnace design R.González, M.J.Quintana, I.Ruiz-Bustinza, F.García, M.A.Barbés, M.F.Barbés. “Cooling efficiency in furnace design”, Dyna, 2013, 80 (182), pp. 131-137.
During fusion, reduction or thermal treatment of a steel charge, the input of energy (either chemical or
electrical) is indispensable to guarantee the viability of the process. Under these circumstances, it will be
reasonable to design the furnace lining in such a way that heat loss through the walls is minimized.
Nevertheless, it can be proved that, for some situations, it is more efficient to withdraw as much heat as
possible from the walls than trying to thermally isolate the system. The work presents recommendations for the
design of walls and cooling systems in furnaces obtained by quantitative analysis of temperatures reached in
specific locations of the furnace using the nodal wear model. The analysis indicates that the wear process of
the lining may be controlled if all the elements that intervene in the process are known.
Structural ultrafine grained steels obtained by advanced controlled rolling R.González, J.O.García, M.A.Barbés, M.J.Quintana, L.F.Verdeja, J.I.Verdeja, “Structural ultrafine grained steels obtained by advanced controlled rolling”, Journal of Iron and Steel Research, International, 2013, 20 (1), pp. 62-7.
Steels with ultrafine grains (lower than 5 μπα) , which usually known as ultrafine ferrite or ultrafine grained
materials, are presently the object of intense research, because of the improvement in resistance and fracture
toughness they may reach compared to conventional steels (with grain sizes above this value). It is shown that
the forenamed steels designated in the Euronorm EN 10149-2, which are manufactured by advanced techniques
of controlled rolling and mainly used in automotive industry, have an ultrafine grain size in the range of 2. 5 to
3. 5 μπι, and with elastic yield stresses higher than 400 MPa. Based on the Morrison-Miller criterion, it is
shown that values of the strain-hardening coefficient lower than 0. 08 would make the industrial application of
these steels unfeasible.
ENVIRONMENT REFRACTORY FLUID
TEMPERATURE
DISTANCE
FT
T
LIMIT
LAYER
M
eT
WM
eT -
IWM
eT --
IWM
liT --
-
CWM
eT --
M
iTIWM
iT --
WM
iT -
CWM
iT --
M
= Metal
= Nodal temperature
Metal – Refractory
= Nodal temperature
Metal – Refractory
effect of corrosion
wear
= Nodal temperature
Metal – Refractory
corrosion wear and
external cooling
= Nodal temperature
Metal – Refractory
effect of corrosion
wear and external
insulating refractory
layer
MM
iT
IWM
eT --
DENSE
REFRACTORYInsulating
Refractory
CWM
iT --
WM
iT -
ENVIRONMENT REFRACTORY FLUID
TEMPERATURE
DISTANCE
FT
T
LIMIT
LAYER
M
eT
WM
eT -
IWM
eT --
IWM
liT --
-
CWM
eT --
M
iTIWM
iT --
WM
iT -
CWM
iT --
M
= Metal
= Nodal temperature
Metal – Refractory
= Nodal temperature
Metal – Refractory
effect of corrosion
wear
= Nodal temperature
Metal – Refractory
corrosion wear and
external cooling
= Nodal temperature
Metal – Refractory
effect of corrosion
wear and external
insulating refractory
layer
MM
iT
IWM
eT --
DENSE
REFRACTORYInsulating
Refractory
CWM
iT --
WM
iT -
y = 18.519x2 + 6.8519x + 1.5296
R2 = 0.978
y = 27.778x2 - 19.722x + 15.744
R2 = 0.95
0
2
4
6
8
10
12
14
16
18
20
0.08 0.1 0.12 0.14 0.16 0.18 0.2
n
AS
TM
G
L (m
m)
Mean linear intercept L (mm)
Average ASTM G
Upper confidence level of G
Lower confidence level of G
S500 and S600
S315S420
2
4
6
Superplastic HSLA steels:microstructure and failure S.Fernandez, M.J.Quintana, J.O.García, L.F.Verdeja, R.Gonzalez and J.I.Verdeja, “Superplastic HSLA steels:microstructure and failure”, Journal of Failure Analysis and Prevention, Vol 13, Issue 3, February 2013, p. 368-376.
Certain materials can show superplasticity when traction tested at temperatures higher than 50% of their
melting point and with low strain rates (ε <〖 10〗 ^(-2) s^(-1)), showing very high elongations (>100%) without
localized necking and mainly intergranular fractures. This behavior requires that the starting grain size is small
(<10 μm) so the flow of matter can be non-homogeneous (sliding and rotating of the grain boundaries,
accommodated by diffusion). This works presents the superplastic characteristic of a shipbuilding steel
deformed at 800°C and a strain rate slower than 〖 10〗 ^(-3) s^(-1). The fine grain size (5 µm) is obtained
when using Nb as a microalloying element and manufactured by controlled rolling processes (3 stages). After
the superplastic deformation, the steel presents mixed fractures: by decohesion of the hard (pearlite and
carbides) and ductile (ferrite) phases and by intergranular sliding of ferrite/ferrite and ferrite/pearlite, just as it
happens in the stage III of the creep behavior. This is confirmed through the Ashby-Verrall model, according to
which the dislocation creep (power-law creep) and diffusion creep (linear-viscous creep) occur simultaneously.
Microstructural Changes of a Construction Steel Caused by Hot Deformation Conference MS&T 2013. J.I.Verdeja, M.J.Quintana, R.González, L.F.Verdeja. “Microstructural Changes of a Construction Steel Caused by Hot Deformation”. October 27-31, 2013, Montreal, Quebec, Canada, Advanced Steel Metallurgy: Design, Processing, and Technological Exploitation, pp. 337-345
A construction steel (shipbuilding strip) obtained by Advanced Thermomechanical Controlled Rolling Processes
presents a room temperature banded ferrite-pearlite microstructure, and when superplastically deformed at
800°C with a strain rate of 5.85x10-5 s-1, the bands disappear as there is grain boundary sliding and grain
cluster rotation. Nevertheless, the superplastic deformation does not imply a decrease in mechanical properties,
as room temperature tests with strain rates of 1.46x10-3 s-1 with the steel previously deformed in
superplastic conditions (until a 110% of straining) result in similar mechanical data. If the steel is deformed at
750°C with low strain rates, cooling results in a microstructure formed only by ferrite and carbides (the
pearlitic phase disappears). This behavior may be explained, from a thermodynamical point of view, by the
effect of negative hydrostatic pressure during the tensile test and the pronounced ferrite- and carbide-former
capacity of Ti and Nb microalloying elements. The samples, tensile tested, in both the hot rolled raw state and
superplastically deformed and then room temperature tested, show in the fracture surface SEM analysis almost
identical features: decohesions surrounding MnS and (C,N)(Ti,Nb) precipitates and between ferrite and pearlite
grains, as well as bedding.
Mechanical behaviour of thermomechanically produced ultrafine grained dual-phase steels R.Gonzalez, J.O.Garcia, L.F.Verdeja, M.J.Quintana and J.I. Verdeja, Mechanical behaviour of thermomechanically produced ultrafine grained dual-phase steels, Canadian Metallurgical Quarterly, Vol. 53, No. 1, 2014, p. 100-106. Double-phase steels are an excellent alternative in the production of automotive parts that require high
mechanical resistance, high impact strength and elevated elongation. These materials are produced using low-
alloy steels as a basis, reducing costs and resulting in a combination of martensite and ferrite structures with
ultrafine grain sizes. These characteristics are accomplished through a strict control of rolling conditions: strain
rate, cooling rate and coiling temperature. This work presents the results of tension testing of two types of
dual-phase steels, along with microstructural characterization, in order to understand the effect of the
advanced thermomechanical controlled rolling processes on the formation of the microstructure and the
resulting mechanical properties.
Tribo-corrosion protection of valves and rotors using cermet layers applied with HVOF JSanchez, M.A,Barbes, R.Gonzalez, L.F.Vedeja, “Tribo-corrosion protection of valves and rotors using cermet layers applied with HVOF”, International Conference on Innovative Manufacturing Technology IMT2013, Krakow, Poland, November 2013, p 111-117.
The economic viability of equipment in industrial facilities that perform organic processes depends on the
capacity of auxiliary equipment, such as valves or rotors, to withstand wear of the tribo-corrosion type
(combination of heat and an aqueous medium). The use of Surface Engineering Techniques such as High
Velocity Oxy-Fuel (HVOF) in order to apply carbide based cermet layers is showing very positive results in
decreasing tribological and corrosion mechanisms; though some industries continue to use wear resistant bulk
materials. Three different carbide layers were applied to a ferritic-pearlitic steel in order to characterize
properties such as adhesion to the substrate, porosity and layer thickness:
Layer Type
1 WC + (Co-Cr)
2 70% [Cr3C2 + (Ni-Cr)] + 30% [WC + (Co-Cr)]
3 Cr3C2 + (Ni-Cr)
An example of a real rotatory equipment after a working campaign, both with and without protective layer is
presented. The capacity of the protective layer to extend the life of parts like the one analyzed is evident even
if zones of the layer are detached during the campaign.
Effect of Pressure in the Microstructure of Die Cast Al-8.5Si-3.5Cu Alloys M.A.Barbés, J.I.Verdeja, M.J.Quintana, L.F.Verdeja, R.González. “Effect of Pressure in the Microstructure of Die Cast Al-8.5Si-3.5Cu Alloys”. 12 al 16 de octubre de 2014, Pittsburgh, Pennsylvania, USA, Advances in Metal Casting Technologies – Process Control, pp. 725-734 The microstructure of Pressure Die Casting of an Al-8.5 Si-3.5 Cu alloy used for clean room tiles shows
amount of constituents (eutectic and Si phases) that do not correspond to the ones indicated by the phase
diagram. Furthermore, there are differences in amount of constituents between the core and the surface zones
of parts produced by this process. The work presents quantitative microstructural analysis of this type of
industrially produced part, and as a possible cause for these differences, simulations of the effect of pressure
on the eutectic (temperature and chemical composition) in the Al-Si system.
As the production rate of these parts is very high, and solidification is very fast, microstructural heterogeneity
may be related to local entrapment of gasses unable to escape during casting.
Thesis:
“Propuesta de Sistema Experto para el Análisis de Fallas en Piezas Metálicas”, José Cruz Mendieta Arroyo,
Licenciatura en Ingeniería Industrial, Universidad Panamericana, Mayo 2009.
“Caracterización Mecánica y Microestructural del Acero Inoxidable Tipo 304 a Temperatura Elevada”, María
José Quintana Hernández, Maestría en Ingeniería, Universidad Panamericana, Diciembre 2010.
Laboratory Facilities at Universidad Panamericana
Mechanical tests: Instron 5583 universal testing machine with 150 kN load cell for tension, compression and 3
point bending (annual calibration), with 50 mm calibrated length extensometer to comply with ASTM-E8 norm
and similar. Capacity to manufacture tensile specimens in the engineering shop.
Measurement of Young´s modulus in long bars using accelerometers.
Hardness: Rockwell durometer for different scales. Micro-hardness: Mitutoyo Vickers micro-durometer with
10 to 1000 g load capacity
Optical Microscopes: microstructure analysis through traditional techniques: sample preparation, grinding and
etching to reveal microstructure. Phase amount (%) and grain size (ASTM number) analysis by manual or
automatic point counting (in collaboration with U. of Oviedo, Spain).
Dimensional Metrology: Brown & Sharp GAGE2000 coordinate machine for parts with aprox 300 mm per side,
dimensional, tolerances, tool wear and inverse engineering analysis.
Scanning Electron Microscopy (SEM): Hitachi TM3030 microscope for metallic, ceramic, polymeric and
biological samples up to 30,000X
Direct collaboration in the SID-MET-MAT group http://www.unioviedo.es/sid-met-mat/
In “SIDerurgia-METalurgia-MATeriales” at Oviedo University, Spain.
NEW!!!!
Refractory and Ceramic Materials Refractory and Ceramic Materials, Luis F. Verdeja, Jose P. Sancho, Antonio Ballester and Roberto Gonzalez, Ed.
SINTESIS, Spain, 2014.
