heat treatment development process for an …
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HEAT TREATMENT DEVELOPMENT PROCESS FOR AN AUTOMOTIVE PART.
Juan José Ramírez-Natera, Rafael Colás, Arheli
Zaid Rodriguez-Diaz, Sergio Haro-Rodriguez
September 25th, 2018.
Allowed CO2 emissions for new automobiles.
• Environmental agencies all over the world have
established the normative to reduce fuel
consumption and emission of greenhouse effect
gases in light vehicles.
• CO2 emissions in the transport sector in the
European Union increased in a 17% in the period
from 1990 to 2014. Light passenger transport
vehicles increased their emissions in 12%, heavy
load transport vehicles doubled it.
• Agencias ambientales alrededor del mundo han
establecido normativas para reducir el consumo de
combustible y emisión de gases contaminantes de
efecto invernadero en vehículos ligeros.
• Las emisiones de CO2 en el sector de transporte
en la unión europea aumentaron en un 17% en el
periodo de 1990 a 2014. Vehículos ligeros de
trasporte de pasajeros aumentó su emisiones en
un 12%, los vehículos de transporte pesado
incrementaron en el doble.
Changes in CO2 emissions in the EU by sector
in 2013-14.
Source
CO2 equivalent
(Millions of metric
tonnes)
Road transportation 6.6
Iron and steel production 5.6
Cement production 3.4
Chemical fuels -3.1
Petroleum refining -4.2
Managed waste disposal sites -4.6
Manufacturing industries
(excluding iron and steel)
-18.1
Commercial -22.5
Residential -65.6
Public electricity and heat
production
-85.1
Total -185.0
Justification• It would be required for industry and
academia to contribute and make an active participation in strategies conducing to increase the efficiency in transportation and reduce fuel consumption and emissions.
• SISAMEX that is involved in the manufacture of components for heavy vehicles have plans to reduce the weight of their components, without impairing the integrity or increasing the risk for failure, to reduce the level of emissions while increasing the load capacity of their vehicles.
• The housing is made of hot rolled carbon steel that is shaped into form within a wide range of temperatures and it is subjected to fatigue due to loading and road conditions.
Justificación• Se requiere que la industria y la
academia contribuyan y participen activamente en estrategias que contribuyan a aumentar la eficiencia en el transporte y reducir el combustible y las emisiones.
• SISAMEX involucrada en la fabricación de componentes para vehículos pesados tiene planes de reducir el peso de sus componentes, sin perjudicar la integridad o aumentar el riesgo de fallas, para reducir el nivel de emisiones y al mismo tiempo aumentar la capacidad de carga de sus vehículos.
• La carcasa está hecha de acero al carbono laminado en caliente que se forma en un amplio rango de temperaturas y está sometida a fatiga debido a la carga y las condiciones de la carretera.
Objective
• Determine by experimental trials normalizing response of two low carbon steels at different normalization and quenching temperatures. Determine also the best combinations of time-temperatures for ageing.
Objetivo
• Determinar mediante pruebas experimentales la respuesta de dos aceros de bajo carbono a diferentes temperaturas de normalización y temple. Y determinar la condición mas favorable de tiempo-temperatura para envejecer los aceros en cuestión.
Experimental procedure
• The housings of the axles are manufactured from hot rolled carbon steel; its thickness varied depending on the type of axle and the loading conditions to which the vehicle will be subjected to.
Procedimiento experimental
• Las fundas de ejes son fabricadas de placa de acero al carbono rolada en caliente. Su espesor varía dependiendo el tipo de eje y las cargas a las cuales el vehículo estará sometido.
• For each cooling media, water or air, 5 different temperatures were used and for ageing 3 temperatures with 3 different dwelling times just for air cooling samples.
• Para cada medio de enfriamiento, aire o agua se usaron 5 diferentes temperaturas de calentamiento. Para el envejecimiento se usaron 3 temperaturas con 3 distintos tiempos para la condición enfriada al aire.
Steels
• Two low carbon Steels were compared both are considered to be an alternative to the one in use for rear axle housing
Aceros
• Se comparan dos aceros de bajo carbono, ambos considerados para sustituir el acero actual usado en fundas de ejes traseros.
Sy
(Mpa)
UTS
(Mpa)
ε
(mm/mm)
Dureza
(HV)
A 504 701 0.262 184
B 510 760 0.293 179
A B
• Samples for heat treatment were machined with a 11 mm thickness plate and 25.4 mm by each side. Heating was made using electric resistance furnace.
• Las muestras para realizar los tratamientos térmicos se han maquinado en una placa de 11 mm de espesor y 25.4 mm por lado. Los calentamientos se realizaron en una mufla eléctrica de resistencias
A B
Water quenched samples
A B
A B
A Steel B Steel
A B
Air cooling samples
A B
A B
A Steel B Steel
Ageing treatments
A Steel B Steel
Samples normalized at 800°C
A Steel B Steel
Samples normalized at 850°C
A Steel B Steel
Samples normalized at 900°C
A Steel B Steel
Samples normalized at 950°C
Conclusions• Two steels with similar chemical
composition were compared as an option to substitute current steel for axle housing.
• Samples of A steel quenched in water has a hardness that ranges from 298 HV to 198 HV, samples of B steel has hardness values of 274 HV to 181 HV depending of quenching temperature.
• The maximum hardness values for A Steel were for 850°C of normalizing temperature. Minimum hardness values were obtained of samples normalized at 750°C.
• The maximum hardness values for B steel were for 950°C of normalizing temperature. Minimum values were for 750°C of normalizing temperature.
Conclusiones• Se compararon dos aceros con una
composición química similar como una opción para sustituir el acero actual por la carcasa del eje.
• Las muestras de acero A templado en agua tienen una dureza que oscila entre 298 HV y 198 HV, las muestras de acero B tienen valores de dureza de 274 HV a 181 HV dependiendo de la temperatura de temple.
• Los valores máximos de dureza para el acero A fueron para una temperatura de 850 ° C de normalización. Se obtuvieron valores mínimos de dureza en muestras normalizadas a 750 °C.
• Los valores de dureza máximos para acero B fueron para muestras normalizadas a 950 ° C. Los valores mínimos fueron para muestras normalizadas a 750 °C.
Conclusions• For samples cooled in air of A steel
minimum values of hardness were found in samples normalized at 850°C.
• Maximum hardness values for B Steel were obtained at 750°C of normalized temperature. Minimum values were found in samples at 800°C.
• For Ageing process 8 temperatures were used with different times.
• A Steel reached its maximum value when is aged at 350°C, samples were normalized at 850°C.
• B Steel reached its maximum value when samples are aged at 250°C normalized at 800°C.
Conclusiones• Para muestras enfriadas en aire de
acero A, se encontraron valores mínimos de dureza en muestras normalizadas a 850 ° C.
• Los valores de dureza máxima para el acero B se obtuvieron de un normalizado a una de temperatura de 750 ° C. Se encontraron valores mínimos en muestras normalizadas a 800 ° C.
• Para el proceso de envejecimiento se usaron 8 temperaturas con diferentes tiempos.
• El acero A alcanzó su valor máximo cuando se envejece a 350°C, las muestras se normalizaron a 850 °C.
• El acero B alcanzó su valor máximo cuando las muestras se envejecen a 250 ° C normalizadas a 800 ° C.
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