01-12-2015, 22:55
Buenas. Acabo de rendir Inglés 1 libre y buscando en internet encontré el texto que tomaron, está acá: http://www.steelconstruction.info/Steel_...properties
NO lo tomaron completo, solo tomaron esta parte:
"Steel derives its mechanical properties from a combination of chemical composition, heat treatment and manufacturing processes. While the major constituent of steel is iron, the addition of very small quantities of other elements can have a marked effect upon the properties of the steel. The strength of steel can be increased by the addition of alloys such as manganese, niobium and vanadium. However, these alloy additions can also adversely affect other properties, such as ductility , toughness and weldability .
Minimizing the sulphur level can enhance ductility , and toughness can be improved by the addition of nickel. The chemical composition for each steel specification is therefore carefully balanced and tested during its production to ensure that the appropriate properties are achieved.
The alloying elements also produce a different response when the material is subjected to heat treatments involving cooling at a prescribed rate from a particular peak temperature. The manufacturing process may involve combinations of heat treatment and mechanical working that are of critical importance to the performance of the steel. Mechanical working takes place as the steel is being rolled or formed. The more steel is rolled, the stronger it becomes. This effect is apparent in the material standards, which tend to specify reducing levels of yield strength with increasing material thickness.
The effect of heat treatment is best explained by reference to the various production process routes that can be used in steel manufacturing, the principal ones being:
- As-rolled steel
- Normalized steel
- Normalized-rolled steel
- Thermomechanically rolled (TMR) steel
- Quenched and tempered (Q&T) steel.
Steel cools as it is rolled, with a typical rolling finish temperature of around 750°C. Steel that is then allowed to cool naturally is termed 'as-rolled' material. Normalizing takes place when as-rolled material is heated back up to approximately 900°C, and held at that temperature for a specific time, before being allowed to cool naturally. This process refines the grain size and improves the mechanical properties, specifically toughness. Normalized-rolled is a process where the temperature is above 900°C after rolling is completed. This has a similar effect on the properties as normalizing, but it eliminates the extra process of reheating the material. Normalized and normalized-rolled steels have an 'N' designation.
The use of high tensile steel can reduce the volume of steel needed but the steel needs to be tough at operating temperatures, and it should also exhibit sufficient ductility to withstand any ductile crack propagation. Therefore, higher strength steels require improved toughness and ductility, which can be achieved only with low carbon clean steels and by maximizing grain refinement. The implementation of the thermomechanical rolling process (TMR) is an efficient way to achieve this. Thermomechanically rolled steel utilises a particular chemistry of the steel to permit a lower rolling finish temperature of around 700°C. Greater force is required to roll the steel at these lower temperatures, and the properties are retained unless reheated above 650°C. Thermomechanically rolled steel has an 'M' designation".
Después había 5 puntos. No me los acuerdo exactos pero eran 4 preguntas escritas en español y había que responderlas en español, y el punto 5 era traducir el último párrafo entero (no te decía literalmente traducir el último párrafo sino que te decía de traducir el párrafo que habla de tal cosa, que bueno, es el último). Las cuatro preguntas no me las acuerdo bien pero eran algo así:
1- Preguntaba por lo que dice el primer y segundo párrafo. Qué ventajas y desventajas trae alterar las proporciones de metales en el acero.
2- Preguntaba lo que dice en el tercer párrafo. Algo así como para qué sirve el tratamiento de temperaturas en el acero.
3- Preguntaba lo que dice en el cuarto párrafo, que enumeres los procesos de producción que están ahí (los 5 guioncitos) y te preguntaba si el texto está completo o falta algo. La respuesta es que no esta completo porque no explica el último proceso (Quenched and tempered (Q&T) steel), ya que el texto está cortado (en el link que les pasé esta completo)
4- Preguntaba lo que está en el quinto párrafo. Que expliques en que consisten los dos procesos de normalización.
5- Y bue el punto 5 como dije es traducir el ultimo párrafo completito.
Espero que les sirva. Lo aprobé con 8. No es difícil, pero tiene bastantes palabras molestas que hay que buscar en el diccionario porque son muy técnicas. Recomiendo que lleven diccionario, lo pueden pedir en la biblioteca media hora antes de rendir, dejando el DNI. Es la única forma en que te lo prestan: no te dejan llevartelo a otra sede o a tu casa ni tampoco con legajo porque es de consulta nomás. Ah, muchos tenían dudas a la salida del parcial por la palabra "rolled". Si les llegan a tomar este texto, significa "laminado".
NO lo tomaron completo, solo tomaron esta parte:
"Steel derives its mechanical properties from a combination of chemical composition, heat treatment and manufacturing processes. While the major constituent of steel is iron, the addition of very small quantities of other elements can have a marked effect upon the properties of the steel. The strength of steel can be increased by the addition of alloys such as manganese, niobium and vanadium. However, these alloy additions can also adversely affect other properties, such as ductility , toughness and weldability .
Minimizing the sulphur level can enhance ductility , and toughness can be improved by the addition of nickel. The chemical composition for each steel specification is therefore carefully balanced and tested during its production to ensure that the appropriate properties are achieved.
The alloying elements also produce a different response when the material is subjected to heat treatments involving cooling at a prescribed rate from a particular peak temperature. The manufacturing process may involve combinations of heat treatment and mechanical working that are of critical importance to the performance of the steel. Mechanical working takes place as the steel is being rolled or formed. The more steel is rolled, the stronger it becomes. This effect is apparent in the material standards, which tend to specify reducing levels of yield strength with increasing material thickness.
The effect of heat treatment is best explained by reference to the various production process routes that can be used in steel manufacturing, the principal ones being:
- As-rolled steel
- Normalized steel
- Normalized-rolled steel
- Thermomechanically rolled (TMR) steel
- Quenched and tempered (Q&T) steel.
Steel cools as it is rolled, with a typical rolling finish temperature of around 750°C. Steel that is then allowed to cool naturally is termed 'as-rolled' material. Normalizing takes place when as-rolled material is heated back up to approximately 900°C, and held at that temperature for a specific time, before being allowed to cool naturally. This process refines the grain size and improves the mechanical properties, specifically toughness. Normalized-rolled is a process where the temperature is above 900°C after rolling is completed. This has a similar effect on the properties as normalizing, but it eliminates the extra process of reheating the material. Normalized and normalized-rolled steels have an 'N' designation.
The use of high tensile steel can reduce the volume of steel needed but the steel needs to be tough at operating temperatures, and it should also exhibit sufficient ductility to withstand any ductile crack propagation. Therefore, higher strength steels require improved toughness and ductility, which can be achieved only with low carbon clean steels and by maximizing grain refinement. The implementation of the thermomechanical rolling process (TMR) is an efficient way to achieve this. Thermomechanically rolled steel utilises a particular chemistry of the steel to permit a lower rolling finish temperature of around 700°C. Greater force is required to roll the steel at these lower temperatures, and the properties are retained unless reheated above 650°C. Thermomechanically rolled steel has an 'M' designation".
Después había 5 puntos. No me los acuerdo exactos pero eran 4 preguntas escritas en español y había que responderlas en español, y el punto 5 era traducir el último párrafo entero (no te decía literalmente traducir el último párrafo sino que te decía de traducir el párrafo que habla de tal cosa, que bueno, es el último). Las cuatro preguntas no me las acuerdo bien pero eran algo así:
1- Preguntaba por lo que dice el primer y segundo párrafo. Qué ventajas y desventajas trae alterar las proporciones de metales en el acero.
2- Preguntaba lo que dice en el tercer párrafo. Algo así como para qué sirve el tratamiento de temperaturas en el acero.
3- Preguntaba lo que dice en el cuarto párrafo, que enumeres los procesos de producción que están ahí (los 5 guioncitos) y te preguntaba si el texto está completo o falta algo. La respuesta es que no esta completo porque no explica el último proceso (Quenched and tempered (Q&T) steel), ya que el texto está cortado (en el link que les pasé esta completo)
4- Preguntaba lo que está en el quinto párrafo. Que expliques en que consisten los dos procesos de normalización.
5- Y bue el punto 5 como dije es traducir el ultimo párrafo completito.
Espero que les sirva. Lo aprobé con 8. No es difícil, pero tiene bastantes palabras molestas que hay que buscar en el diccionario porque son muy técnicas. Recomiendo que lleven diccionario, lo pueden pedir en la biblioteca media hora antes de rendir, dejando el DNI. Es la única forma en que te lo prestan: no te dejan llevartelo a otra sede o a tu casa ni tampoco con legajo porque es de consulta nomás. Ah, muchos tenían dudas a la salida del parcial por la palabra "rolled". Si les llegan a tomar este texto, significa "laminado".