1. UNIT 5 CAUSE & EFFECT Vocabulary Grammar and functions
Heat treatment of steel:
annealing
hardening
Tempering
WORD FORMATION (U2 -> p28): N from Vbs
Grammar and functions
Expressing cause & effect
ALLOW / CAUSE / AVOID

2. CAUSE & EFFECT CAUSE BECAUSE
SINCE + SENTENCE (S+Vb) porque, puesto que, ya que AS
Debido a + NOUN / Vb -ING
DUE TO
BECAUSE OF + NOUN / VB -ING
OWING TO
Debido a QUE + SENTENCE (S+Vb)
DUE TO THE FACT THAT + (Sentence)
BECAUSE OF THE FACT THAT + (Sentence)
OWING TO THE FACT THAT + (Sentence)
ONE EFFECT / RESULT / CONSEQUENCE OF C IS E

3. C RESULTS IN E dar como resultado C BRINGS ABOUT E provocar,
CAUSE & EFFECT
VERBS
C RESULTS IN E dar como resultado
C BRINGS ABOUT E provocar,
C GIVES RISE TO E implicar, suponer
C LEADS TO E lleva/conduce a
C CAUSES/ALLOWS E hace que (+Vb)
C MAKES X + ADJ
Effect: X BECOMES (+adj) resulta + ADJ

4. C SO THAT E de modo que / para que
CAUSE & EFFECT
EFFECT
THEREFORE, por lo tanto
THUS, así,
HENCE, así pues
CONSEQUENTLY,
AS A CONSEQUENCE,
AS A RESULT,
DUE TO THIS, como consecuencia,
THEREBY, de este modo
IN THIS WAY , …
C SO THAT E de modo que / para que

5. EXERCISE We use copper in wires due to its ductility
We mix pure metals with other materials so that we obtain the required properties
Aluminium is used in structures as it is corrosion resistant
Aluminium is used in structures because of its corrosion resistance
Tempering results in a decrease in hardness and ...
Plastics are insulators, thus they are used to cover wires
Annealed steel is more machineable since this process releases internal stresses
With hardening, the metal becomes stronger
Iron is brittle. As a consequence it is mixed with other ...
Alloying is a way of changing the properties of metals. In this way we can obtain materials with specific characteristics

6. QUESTIONS
Which two methods are used to change the properties of steel?
How does the carbon content affect the properties of steel?
What does heat treatment consist of?
What happens when we heat steel at a certain temperature?
Which are the three heat treatments?
What two steps are involved in the process of annealing?
Which are the results?
What happens when we cool the metal quickly?
What two steps are involved in the process of hardening?
What problem results from hardening and how can we solve this?
Explain the process of tempering.
What is the difference between tempered steel and high carbon steel?

7. TRUE/FALSE Carbon makes steel harder. T (up to 1.5%)
When we want to make steel softer and easier to machine we use annealing. T
Annealing increases the internal stresses in the metal. F (Annealing releases stresses)
Steel can be hardened by cooling it slowly. F (by cooling it fast)
High carbon steel can be easily worked because it is soft. F (it becomes hard)

8. WORD FORMATION PercentAGE hammerING contractION crackING temperING
annealiNG
cooliNG
DistortION
treatMENT
hardENING

9. CAUSE/PERMIT/PREVENT
CAUSE: TO CAUSE + OBJ + TO INFINITIVE
TO MAKE + OBJ + BASE FORM OF THE VERB
hacer que + frase
PERMIT: TO PERMIT + OBJECT + TO INFINITIVE
TO ALLOW + OBJECT + TO INFINITIVE
TO ENABLE + OBJECT + TO INFINITIVE
TO LET + OBJECT + BASE FORM OF THE VERB
permitir que + frase
PREVENT: TO PREVENT + OBJECT + FROM + -ING
TO AVOID + OBJECT + FROM + -ING
TO STOP + OBJECT + FROM + -ING
TO KEEP + OBJECT + FROM + -ING
impedir que + frase

10. EXERCISE CAUSE/ALLOW/PREVENT
B permit
C cause
B prevent
A causes
A permit
C prevent
B Permits …… prevents
A Prevent

11. LISTENING: STEEL
an alloy of IRON and up to 1.7% CARBON, with small amounts of manganese, phosphorous, sulfur, and silicon
those with other metals
low-alloy steels have LESS THAN 5% of the alloying metal and high-alloy steels MORE THAN 5%.
Carbon steels are FAR STRONGER THAN IRON, and their properties can be tailored to their uses by adjusting COMPOSITION AND TREATMENT.
STAINLESS STEELS
Steel was first mass-produced in the MID-19TH CENTURY
The USA, the former Soviet Union, and Japan are the MAJOR PRODUCERS.
All steelmaking processes REMOVE THE IMPURITIES in the raw materials …and reduce iron ore BY OXIDIZING them WITH an air or oxygen blast

12. LISTENING: STEEL
THUS MOST OF THE CARBON, SILICON, manganese, phosphorus and sulfur ARE CONVERTED TO THEIR OXIDES and, …
The main processes are …or basic OXYGEN process,
…, used for HIGHEST-QUALITY STEEL; and the open-hearth process.
When THE IMPURITIES HAVE BEEN REMOVED, desired elements are added in calculated proportions
steel is cast as INGOTS that are shaped while still red-hot in rolling mills, or it may be cast as a continuous bar (strand casting).
The PROPERTIES OF CARBON STEELS may be greatly improved by HEAT TREATMENT: ANNEALING, CASE HARDENING and TEMPERING

13. HEAT TREATMENT
1 THE PROPERTIES OF METALS CAN BE CHANGED IN DIFFERENT WAYS. A COMMON METHOD OF IMPROVING THEIR CHARACTERISTICS IS BY ALLOYING SEVERAL METALS. THIS METHOD CONSISTS OF HEATING THE METALS UNTIL THEY MELT IN ORDER TO OBTAIN THE REQUIRED PROPERTIES. FOR EXAMPLE, STEEL CONTAINING LITTLE CARBON WILL be SOFTER than steel with more carbon

14. HEAT TREATMENT
2 ON THE OTHER HAND, THE PROPERTIES OF STEEL CAN ALSO BE IMPROVED BY HEAT TREATMENT. THIS IS THE NAME GIVEN TO A NUMBER OF PROCEDURES WHICH CONSIST OF HEATING THE METAL UP TO A CERTAIN TEMPERATURE AND THEN ALLOW THE METAL TO COOL AT DIFFERENT RATES

15. HEAT TREATMENT
3 ONE OF SUCH PROCEDURES IS KNOWN AS ANNEALING. IN THIS PROCESS, STEEL IS HEATED ABOVE ITS CRITICAL TEMPERATURE AND THEN IT IS COOLED SLOWLY.
4 AS A RESULT, THE METAL BECOMES SOFTER AND MORE EASILY MACHINEABLE DUE TO THE FACT THAT THIS PROCESS PREVENTS INTERNAL STRESSES FROM OCCURRING

16. HEAT TREATMENT
5 AS OPPOSED TO ANNEALING, WE CAN MAKE THE METAL HARDER WITH THE PROCESS OF HARDENING. IN THIS CASE, WE LET THE METAL HEAT ABOVE ITS CRITICAL TEMPERATURE AND THEN WE ALLOW IT TO COOL FAST.
6 ON THE CONTRARY TO WHAT HAPPENED IN THE PROCESS OF ANNEALING, THE METAL OBTAINED WILL BE HARDER; HOWEVER, IT WILL BE BRITTLE SINCE THE RAPID COOLING CAUSES UNEQUAL CONTRACTIONS TO OCCUR IN THE METAL, WHICH GIVES RISE TO CRACKING

17. HEAT TREATMENT
7 IN ORDER TO AVOID THIS PROBLEM, THE METAL CAN BE HEATED BELOW ITS CRITICAL TEMPERATURE AND INSTEAD OF COOLING IT QUICKLY WE LET IT COOL SLOW LY; IN THIS WAY, DESPITE THE METAL BEING HARD, IT WILL ALSO BE TOUGH THUS ALLOWING US TO SHAPE IT WITHOUT FRACTURING