S A E Heat Treatments
: HEAT TREATMENT OF STEEL: The Working Of Steel
The Society of Automotive Engineers have adopted certain heat treatments
to suit different steels and varying conditions. These have already
been referred to on pages 39 to 41 in connection with the different
steels used in automobile practice. These treatments are designated
by letter and correspond with the designations in the table.
HEAT TREATMENTS
Heat Treatment A
1. Carbonize at a temperature between 1,600 deg.F. and 1,750 deg.F.
(1,650-1,700 deg.F. desired.)
2. Cool slowly or quench.
3. Reheat to 1,450-1,500 deg.F. and quench.
Heat Treatment B
After forging or machining:
1. Carbonize between 1,600 deg.F. and 1,750 deg.F. (1,650-1,700 deg.F.
Desired.)
2. Cool slowly in the carbonizing mixture.
3. Reheat to 1,550-1,625 deg.F.
4. Quench.
5. Reheat to 1,400-1,450 deg.F.
6. Quench.
7. Draw in hot oil at 300 to 450 deg.F., depending upon the degree of
hardness desired.
Heat Treatment D
After forging or machining:
1. Heat to 1,500-1,600 deg.F.
2. Quench.
3. Reheat to 1,450-1,500 deg.F.
4. Quench.
5. Reheat to 600-1,200 deg.F. and cool slowly.
Heat Treatment E
After forging or machining:
1. Heat to 1,500-1,550 deg.F.
2. Cool slowly.
3. Reheat to 1,450-1,500 deg.F.
4. Quench.
5. Reheat to 600-1,200 deg.F. and cool slowly.
Heat Treatment F
After shaping or coiling:
1. Heat to 1,425-1,475 deg.F.
2. Quench in oil.
3. Reheat to 400-900 deg.F., in accordance with temper desired and cool
slowly.
Heat Treatment G
After forging or machining:
1. Carbonize at a temperature between 1,600 deg.F. and 1,750 deg.F.
(1,650-1,700 deg.F. desired).
2. Cool slowly in the carbonizing mixture.
3. Reheat to 1,500-1,550 deg.F.
4. Quench.
5. Reheat to 1,300-1,400 deg.F.
6. Quench.
7. Reheat to 250-500 deg.F. (in accordance with the necessities of the case)
and cool slowly.
Heat Treatment H
After forging or machining:
1. Heat to 1,500-1,600 deg.F.
2. Quench.
3. Reheat to 600-1,200 deg.F. and cool slowly.
Heat Treatment K
After forging or machining:
1. Heat to 1,500-1,550 deg.F.
2. Quench.
3. Reheat to 1,300-1,400 deg.F.
4. Quench.
5. Reheat to 600-1,200 deg.F. and cool slowly.
Heat Treatment L
After forging or machining:
1. Carbonize between 1,600 deg.F. and 1,750 deg.F. (1,650-1,700 deg.F. desired).
2. Cool slowly in the carbonizing mixture.
3. Reheat to 1,400-1,500 deg.F.
4. Quench.
5. Reheat to 1,300-1,400 deg.F.
6. Quench.
7. Reheat to 250-500 deg.F. and cool slowly.
Heat Treatment M
After forging or machining:
1. Heat to 1,450-1,500 deg.F.
2. Quench.
3. Reheat to 500-1.250 deg.F. and cool slowly.
Heat Treatment P
After forging or machining:
1. Heat to 1,450-1,500 deg.F.
2. Quench.
3. Reheat to 1,375-1,450 deg.F. slowly.
4. Quench.
5. Reheat to 500-1,250 deg.F. and cool slowly.
Heat Treatment Q
After forging:
1. Heat to 1,475-1,525 deg.F. (Hold at this temperature one-half hour,
to insure thorough heating.)
2. Cool slowly.
3. Machine.
4. Reheat to 1,375-1,425 deg.F.
5. Quench.
6. Reheat to 250-550 deg.F. and cool slowly.
Heat Treatment R
After forging:
1. Heat to 1,500-1,550 deg.F.
2. Quench in oil.
3. Reheat to 1,200-1,300 deg.F. (Hold at this temperature three hours.)
4. Cool slowly.
5. Machine.
6. Reheat to 1,350-1,450 deg.F.
7. Quench in oil.
8. Reheat to 250-500 deg.F. and cool slowly.
Heat Treatment S
After forging or machining:
1. Carbonize at a temperature between 1,600 and 1,750 deg.F.
(1,650-1,700 deg.F. Desired.)
2. Cool slowly in the carbonizing mixture.
3. Reheat to 1,650-1,750 deg.F.
4. Quench.
5. Reheat to 1,475-1,550 deg.F.
6. Quench.
7. Reheat to 250-550 deg.F. and cool slowly.
Heat Treatment T
After forging or machining:
1. Heat to 1,650-1,750 deg.F.
2. Quench.
3. Reheat to 500-1,300 deg.F. and cool slowly.
Heat Treatment U
After forging:
1. Heat to 1,525-1,600 deg.F. (Hold for about one-half hour.)
2. Cool slowly.
3. Machine.
4. Reheat to 1,650-1,700 deg.F.
5. Quench.
6. Reheat to 350-550 deg.F. and cool slowly.
Heat Treatment V
After forging or machining:
1. Heat to 1,650-1,750 deg.F.
2. Quench.
3. Reheat to 400-1,200 deg.F. and cool slowly.
More
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Steel that has been hardened is generally harder and more brittle than is necessary, and in order to bring it to the condition that meets our requirements a treatment called tempering is used. This increases the toughness of the steel, i.e., decrea...