US1296649A - Process of heat treatment of steel. - Google Patents
Process of heat treatment of steel. Download PDFInfo
- Publication number
- US1296649A US1296649A US86670214A US1914866702A US1296649A US 1296649 A US1296649 A US 1296649A US 86670214 A US86670214 A US 86670214A US 1914866702 A US1914866702 A US 1914866702A US 1296649 A US1296649 A US 1296649A
- Authority
- US
- United States
- Prior art keywords
- steel
- temperature
- heating
- heat treatment
- treatment
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired - Lifetime
Links
- 229910000831 Steel Inorganic materials 0.000 title description 23
- 239000010959 steel Substances 0.000 title description 23
- 238000010438 heat treatment Methods 0.000 title description 16
- 238000000034 method Methods 0.000 title description 9
- 238000011282 treatment Methods 0.000 description 10
- 239000000463 material Substances 0.000 description 4
- 238000009792 diffusion process Methods 0.000 description 3
- 239000000203 mixture Substances 0.000 description 3
- 239000003921 oil Substances 0.000 description 3
- 238000005496 tempering Methods 0.000 description 3
- 230000009466 transformation Effects 0.000 description 3
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 3
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 2
- PWHULOQIROXLJO-UHFFFAOYSA-N Manganese Chemical compound [Mn] PWHULOQIROXLJO-UHFFFAOYSA-N 0.000 description 2
- PXHVJJICTQNCMI-UHFFFAOYSA-N Nickel Chemical compound [Ni] PXHVJJICTQNCMI-UHFFFAOYSA-N 0.000 description 2
- OAICVXFJPJFONN-UHFFFAOYSA-N Phosphorus Chemical compound [P] OAICVXFJPJFONN-UHFFFAOYSA-N 0.000 description 2
- XUIMIQQOPSSXEZ-UHFFFAOYSA-N Silicon Chemical compound [Si] XUIMIQQOPSSXEZ-UHFFFAOYSA-N 0.000 description 2
- 229910052799 carbon Inorganic materials 0.000 description 2
- 239000010962 carbon steel Substances 0.000 description 2
- 238000001816 cooling Methods 0.000 description 2
- 229910052748 manganese Inorganic materials 0.000 description 2
- 239000011572 manganese Substances 0.000 description 2
- 229910052698 phosphorus Inorganic materials 0.000 description 2
- 239000011574 phosphorus Substances 0.000 description 2
- 229910052710 silicon Inorganic materials 0.000 description 2
- 239000010703 silicon Substances 0.000 description 2
- 238000010583 slow cooling Methods 0.000 description 2
- 229910000975 Carbon steel Inorganic materials 0.000 description 1
- VYZAMTAEIAYCRO-UHFFFAOYSA-N Chromium Chemical compound [Cr] VYZAMTAEIAYCRO-UHFFFAOYSA-N 0.000 description 1
- 229910001208 Crucible steel Inorganic materials 0.000 description 1
- NINIDFKCEFEMDL-UHFFFAOYSA-N Sulfur Chemical compound [S] NINIDFKCEFEMDL-UHFFFAOYSA-N 0.000 description 1
- 238000000137 annealing Methods 0.000 description 1
- 229910052804 chromium Inorganic materials 0.000 description 1
- 239000011651 chromium Substances 0.000 description 1
- 239000000470 constituent Substances 0.000 description 1
- 229910021385 hard carbon Inorganic materials 0.000 description 1
- 238000004519 manufacturing process Methods 0.000 description 1
- 229910052759 nickel Inorganic materials 0.000 description 1
- 238000010791 quenching Methods 0.000 description 1
- 230000000171 quenching effect Effects 0.000 description 1
- QEVHRUUCFGRFIF-MDEJGZGSSA-N reserpine Chemical compound O([C@H]1[C@@H]([C@H]([C@H]2C[C@@H]3C4=C(C5=CC=C(OC)C=C5N4)CCN3C[C@H]2C1)C(=O)OC)OC)C(=O)C1=CC(OC)=C(OC)C(OC)=C1 QEVHRUUCFGRFIF-MDEJGZGSSA-N 0.000 description 1
- 230000035939 shock Effects 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 238000000844 transformation Methods 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C21—METALLURGY OF IRON
- C21D—MODIFYING THE PHYSICAL STRUCTURE OF FERROUS METALS; GENERAL DEVICES FOR HEAT TREATMENT OF FERROUS OR NON-FERROUS METALS OR ALLOYS; MAKING METAL MALLEABLE, e.g. BY DECARBURISATION OR TEMPERING
- C21D1/00—General methods or devices for heat treatment, e.g. annealing, hardening, quenching or tempering
- C21D1/18—Hardening; Quenching with or without subsequent tempering
- C21D1/19—Hardening; Quenching with or without subsequent tempering by interrupted quenching
Definitions
- This invention relates to an improved heat treatment in the manufacture of any article of ingot or wrought'steel and especially of 11 parts and armor plates.
- the ob] ect of this invention is to diminish the brittleness of the material while increasing its strength and elongation under tensile stress, and its tenacity (that is, its power to resist. shock).
- the improved heattreatment is differentiated essentially from the other treatments proposed hitherto, by the fact that in the known treatments the heating before hardening is effected at a single temperature, the value of which is determined by the latest point of transformation of the steel, whereas according to the resent improved process the heating for the ardening is efiected successively at two different strictly determined temperatures, the passage from the first temperature to the second temperature being gradually effected.
- the first temperature is comprised in the interval in which the diffusion phenomena of the different components in the struc-' tural elements of the steel occur with the greatest rapidity, without injuriously affecting the strength of the steel.
- the steel under treatment must therefore be heated to a temperature which is at least 100 (lhigher than the third transformation point on heating of the steel in question.
- the said interval varies in amplitude and position according to the composition of the steel; but itcan be surely and easily determined by means of mechanical or micrographic tests or thermic analysis.
- the second temperature is 30 C. lower at least than the one which is employed for producin the ordinary homogeneous. tem per. Thls second temperature 1s slightly Specification of. I.etters'Patent. Patented DIar, 11,1919,
- the article to be treated (which may consist either of a rough rolled or rough wrought or a previously heat treated material) is first gradually heated in a suitable furnace until the entire mass of the article has reached the aforesaid first temperature.
- This first temperature is maintained constant during an interval of time, experimentally determined, which may vary between very large limits according to the properties of the steel and the shape and the dimensions of the treated articles. For a semi-hard carbon steel this interval may vary from one hour or less for pieces of 2-3 kg. or less to 20 hours or more for ieces of 10 tons or more.
- T e temperature of the furnace is next gradually changed to the aforesaid second perature or first heating.
- the article is then quenched in cold or warm water or in oil, or is hardened by sprinkling.
- This treatment is generally followed by one of the ordinary tempering 0r re-heating (annealing)- processes when a material with high tenacity and elongation is desired; or it may be followed by one of the well known tempering or hardening processes if it is intended to produce a material having a high degree of hardnesspol b one of the o'rdinary processes for pro ucing a negative hardness (softening) of the articles having a heterogeneous com osition, which results partly in a hard an artly in a tenacious texture of the article a ter treatment.
- a steel article for example, a connecting an interval of 2 hours.
- the treatment would be effected as follows (1) Heating gradually to a temperature of about 900 C.-
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Physics & Mathematics (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Heat Treatment Of Steel (AREA)
- Heat Treatment Of Articles (AREA)
- Heat Treatment Of Strip Materials And Filament Materials (AREA)
Description
FEDERICO GIOLITTI, OF TUB/III, ITALY, ASSIGNOR TO SOCIETA ANONIMA ITALIANA GIO,
ANSALDO & (3., OF GENOA, ITALY.
PROCESS OF HEAT TBEATMENTOF STEEL.
No Drawing.
To all whom it may concern:
Be it known that I, Fnnnnrco Gronrr'rr, a
subject of the King of Italy, residin at No.
7 5 Stradale Moncalieri, in Turin, Ita y, have invented certain new and useful Improvements in Processes of Heat Treatment of Steel, of which the following is a specification.
This invention relates to an improved heat treatment in the manufacture of any article of ingot or wrought'steel and especially of 11 parts and armor plates.
The ob] ect of this invention is to diminish the brittleness of the material while increasing its strength and elongation under tensile stress, and its tenacity (that is, its power to resist. shock).
The improved heattreatment is differentiated essentially from the other treatments proposed hitherto, by the fact that in the known treatments the heating before hardening is effected at a single temperature, the value of which is determined by the latest point of transformation of the steel, whereas according to the resent improved process the heating for the ardening is efiected successively at two different strictly determined temperatures, the passage from the first temperature to the second temperature being gradually effected.
The temperatures above referred to are determined as follows:
1. The first temperature is comprised in the interval in which the diffusion phenomena of the different components in the struc-' tural elements of the steel occur with the greatest rapidity, without injuriously affecting the strength of the steel.
The steel under treatment must therefore be heated to a temperature which is at least 100 (lhigher than the third transformation point on heating of the steel in question.
As is well known, the said interval varies in amplitude and position according to the composition of the steel; but itcan be surely and easily determined by means of mechanical or micrographic tests or thermic analysis.
2. The second temperature is 30 C. lower at least than the one which is employed for producin the ordinary homogeneous. tem per. Thls second temperature 1s slightly Specification of. I.etters'Patent. Patented DIar, 11,1919,
A nc tionmed October 14, 1914. Serial No. 866,702.
treated steel, but it is necessary in practice to exceed this limit, more or less, according to the shape and dimensions of themanufactured articles and their composition.
An example of the mode of application of the improved treatment is the following: The article to be treated (which may consist either of a rough rolled or rough wrought or a previously heat treated material) is first gradually heated in a suitable furnace until the entire mass of the article has reached the aforesaid first temperature. This first temperature is maintained constant during an interval of time, experimentally determined, which may vary between very large limits according to the properties of the steel and the shape and the dimensions of the treated articles. For a semi-hard carbon steel this interval may vary from one hour or less for pieces of 2-3 kg. or less to 20 hours or more for ieces of 10 tons or more.
T e temperature of the furnace is next gradually changed to the aforesaid second perature or first heating. The article is then quenched in cold or warm water or in oil, or is hardened by sprinkling. This treatment is generally followed by one of the ordinary tempering 0r re-heating (annealing)- processes when a material with high tenacity and elongation is desired; or it may be followed by one of the well known tempering or hardening processes if it is intended to produce a material having a high degree of hardnesspol b one of the o'rdinary processes for pro ucing a negative hardness (softening) of the articles having a heterogeneous com osition, which results partly in a hard an artly in a tenacious texture of the article a ter treatment.
To give a practical example for the treatment of a determined object formed of a determined steel we are now going to describe the following case cut application is a cylinder having a diameter of'50 centimeters and a length of 6 meters, made of cast steel of the following com- The third transformationpointon heating of a steel of this composition is in the neighborhood of, 900 0., while the corresponding point on the cooling curve is between 580'600 C.
From the tests made it appears that thebest thermical treatment for this steel according to the principles of the processes subject-matter of the present application is the following one (1) Slow heating during about 18 hours.
' up to a uniform temperature of 1070 C. throughout the whole mass of the piece.
(2) Maintaining the above said temperature of 1070 C. for six hours.
(3) Slowcooling (during about six hours) down to a uniform temperature of 680 C. v (4:) Maintaining the above temperature of680 C. for about six hours.
Quenching in oil at ordinary temperature. 7
I With a steel containing the constituents referred to in the proportions given below,
the region in which the diffusion phenomena.
occur with the greatest rapidity on heating will be found to be between 980 and 1050 0.,
and on cooling, inthe neighborhood of 700750 C Carbon ;'i; o. 40
Manganese 0.60 Silicon 0.15 Sulfur--- 0.009% Phosphorus 0.02 Chromium 2.20 Nickel 2.50
. A steel article, for example, a connecting an interval of 2 hours.
(c) Quenched in water from a temperature of 800 C.
\Vith a carbon steel containing the constituentls specified below in the proportion set fort I Carbon 0.45 Manganese 0. 52 Silicon 0.10 Sulfur 0.05 Phosphorus 0.004%
the treatment would be effected as follows (1) Heating gradually to a temperature of about 900 C.-
'(2) Maintainingthe steel at this temperature for from Q'to 12 hours.
(3) Slow cooling to about 800 C.
' (4:) Maintaining the steel at this temperature for a period .equ'al to one-half that stated under (1).
(5) Hardening in warm water or oil at the ordinary temperature. a
(6) If necessary, tempering to obtain the desired tensile strength.
Having now described my invention, what I claim as new and desire to secure by Letters Patent is The process of heat treatment of steel which comprises heating the steel to a temperature .in the neighborhood of that at which the diffusion phenomena of the different components of the steel take place with the greatest rapidity, that is to say at least 100 C. higher than the third transforma tion point on heating of the steel under treatment, then, lowering its temperature to at least 30 C. below the temperature necessary for effecting the ordinary uniform hardening and therefore at least about 50 C. above the critical point Ar In testimony whereof I have signed my name to this specification in the presence of two subscribing witnesses.
' FEDERICO GIOLITTI' Witnesses: I
GIAcoMo CARnAnA, v A. Bonaomo.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86670214A US1296649A (en) | 1914-10-14 | 1914-10-14 | Process of heat treatment of steel. |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86670214A US1296649A (en) | 1914-10-14 | 1914-10-14 | Process of heat treatment of steel. |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US1296649A true US1296649A (en) | 1919-03-11 |
Family
ID=3364198
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US86670214A Expired - Lifetime US1296649A (en) | 1914-10-14 | 1914-10-14 | Process of heat treatment of steel. |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US1296649A (en) |
-
1914
- 1914-10-14 US US86670214A patent/US1296649A/en not_active Expired - Lifetime
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