EP0103717B1 - Bain de sel inerte pour le chauffage de l'acier - Google Patents
Bain de sel inerte pour le chauffage de l'acier Download PDFInfo
- Publication number
- EP0103717B1 EP0103717B1 EP83107597A EP83107597A EP0103717B1 EP 0103717 B1 EP0103717 B1 EP 0103717B1 EP 83107597 A EP83107597 A EP 83107597A EP 83107597 A EP83107597 A EP 83107597A EP 0103717 B1 EP0103717 B1 EP 0103717B1
- Authority
- EP
- European Patent Office
- Prior art keywords
- regenerator
- polymeric
- salt bath
- bath
- salt
- 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
Links
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
- C21D1/34—Methods of heating
- C21D1/44—Methods of heating in heat-treatment baths
- C21D1/46—Salt baths
Definitions
- the invention relates to an inert salt bath for heating steels to austenitizing temperatures, consisting of a mixture of essentially alkali and alkaline earth chlorides and a regenerator.
- the parts To harden beam parts such as tools, the parts must be heated to the austenitizing temperature. In many cases, this heating takes place in salt baths. However, heating in the salt bath must be such that the surface of the components to be hardened does not undergo any chemical changes.
- the salt baths used should therefore, for example, neither exert an oxygen effect, which could result in decarburization, nor should carburization take place, which may lead to melting and thus destruction of the workpieces at appropriate hardening temperatures. Nor should they have a corrosive effect.
- Salt melts for heating steel parts to the austenitizing temperature generally contain chlorides of alkali and alkaline earth metals, mostly chlorides of sodium, potassium and barium.
- the composition depends on the particular application, in particular on the working temperature, i.e. the melting point of the salt mixture. Melting of this type, which are made from very pure substances, generally meet the requirements placed on the surface quality, they are inert.
- the production of such glow baths from very pure substances is very expensive, so that lower-quality starting materials have to be used and the baths' inertness is thus lost.
- even originally inert glow baths lose their inert character due to the introduction of impurities, in particular the inevitable introduction of iron oxide, detergent residues, processing oils, etc. This not only leads to decarburization of the workpieces, but also to an increased corrosion attack on the components and the electrodes of the furnaces containing the molten salts and thus at higher costs.
- regenerators or regeneration processes are used. It is known that molten salt for high-temperature baths, for example for hardening high-speed steel, can be added with methyl chloride, thereby avoiding decarburization. However, the success of this treatment is often not sufficient and in any case only temporarily, since methyl chloride must not be introduced into the melt during the treatment of workpieces.
- regenerators are e.g. Silicon or silicon carbide.
- the silicon generally fulfills the desired purpose, i.e. prevents decarburization, but occasionally the silicon is sintered onto the workpiece surface, which may result in irreparable damage. In addition, it generally forms a tough sludge in the molten salt that is difficult to remove.
- Silicon carbide has practically the same disadvantages as silicon itself, but above all it cannot be used if carburizing of the workpiece surface must be avoided under all circumstances.
- This object was achieved according to the invention by adding 0.01 to 2% by weight of a carbon and nitrogen-containing polymeric organic compound to the salt mixture as regenerator. These compounds can be added to the bath during operation or during the preparation of the salt mixture or salts.
- Polymeric triazine compounds, polymeric hydrocyanic acids, polymeric carboxamides and / or polymeric urea have proven particularly useful as regenerators.
- the degree of polymerization must be chosen so that the reaction in the bath is not too stormy. In some cases degrees of polymerization n> 3 are already sufficient, but they are preferably much higher.
- Suitable regenerators are triaminotriazine-formaldehyde condensation products and in particular melon, a polymerization product of f ⁇ / ! E! Amine, which can be prepared by heating melamine to temperatures of 500.degree.
- nitrogen-containing polymeric organic compounds such as cyanuric acid or azulmic acid, have also proven successful.
- the baths can be operated at temperatures from 700 to 1300 ° C.
Landscapes
- Chemical & Material Sciences (AREA)
- Engineering & Computer Science (AREA)
- Thermal Sciences (AREA)
- Crystallography & Structural Chemistry (AREA)
- Mechanical Engineering (AREA)
- Materials Engineering (AREA)
- Metallurgy (AREA)
- Organic Chemistry (AREA)
- Physics & Mathematics (AREA)
- Seasonings (AREA)
- Anti-Oxidant Or Stabilizer Compositions (AREA)
- Compositions Of Macromolecular Compounds (AREA)
- Devices For Medical Bathing And Washing (AREA)
- Curing Cements, Concrete, And Artificial Stone (AREA)
- Nitrogen Condensed Heterocyclic Rings (AREA)
- Heat Treatment Of Steel (AREA)
- Cosmetics (AREA)
- Lubricants (AREA)
- Cleaning And De-Greasing Of Metallic Materials By Chemical Methods (AREA)
- Heat Treatment Of Articles (AREA)
- Chemical Treatment Of Metals (AREA)
- Electroplating And Plating Baths Therefor (AREA)
Claims (3)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
AT83107597T ATE18921T1 (de) | 1982-08-25 | 1983-08-02 | Inertes salzbad zum erwaermen von staehlen. |
Applications Claiming Priority (2)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE19823231540 DE3231540A1 (de) | 1982-08-25 | 1982-08-25 | Inertes salzbad zum erwaermen von staehlen |
DE3231540 | 1982-08-25 |
Publications (2)
Publication Number | Publication Date |
---|---|
EP0103717A1 EP0103717A1 (fr) | 1984-03-28 |
EP0103717B1 true EP0103717B1 (fr) | 1986-04-02 |
Family
ID=6171642
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
EP83107597A Expired EP0103717B1 (fr) | 1982-08-25 | 1983-08-02 | Bain de sel inerte pour le chauffage de l'acier |
Country Status (12)
Country | Link |
---|---|
EP (1) | EP0103717B1 (fr) |
JP (1) | JPS5938324A (fr) |
AT (1) | ATE18921T1 (fr) |
BR (1) | BR8304569A (fr) |
DE (2) | DE3231540A1 (fr) |
DK (1) | DK152224C (fr) |
ES (1) | ES8405084A1 (fr) |
IL (1) | IL69419A (fr) |
IN (1) | IN160848B (fr) |
TR (1) | TR21551A (fr) |
YU (1) | YU153383A (fr) |
ZA (1) | ZA835229B (fr) |
Family Cites Families (3)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE622802C (de) * | 1932-04-15 | 1935-12-06 | Emil Kleisinger Dr | Erhitzungsbad |
DE1233423B (de) * | 1961-04-28 | 1967-02-02 | Ici Ltd | Verfahren zum Regenerieren eines zyanid-freien, geschmolzenen, zur Waermebehandlung von Metallen benutzten Salzbades |
DE1264475B (de) * | 1966-05-05 | 1968-03-28 | Degussa | Salzbad zur Waermebehandlung von Stahl |
-
1982
- 1982-08-25 DE DE19823231540 patent/DE3231540A1/de not_active Withdrawn
-
1983
- 1983-07-08 JP JP58123556A patent/JPS5938324A/ja active Granted
- 1983-07-15 YU YU01533/83A patent/YU153383A/xx unknown
- 1983-07-18 ZA ZA835229A patent/ZA835229B/xx unknown
- 1983-07-30 IN IN951/CAL/83A patent/IN160848B/en unknown
- 1983-08-02 AT AT83107597T patent/ATE18921T1/de not_active IP Right Cessation
- 1983-08-02 DE DE8383107597T patent/DE3362793D1/de not_active Expired
- 1983-08-02 EP EP83107597A patent/EP0103717B1/fr not_active Expired
- 1983-08-02 TR TR21551A patent/TR21551A/xx unknown
- 1983-08-03 IL IL69419A patent/IL69419A/xx unknown
- 1983-08-23 DK DK385283A patent/DK152224C/da not_active IP Right Cessation
- 1983-08-24 ES ES525120A patent/ES8405084A1/es not_active Expired
- 1983-08-24 BR BR8304569A patent/BR8304569A/pt not_active IP Right Cessation
Also Published As
Publication number | Publication date |
---|---|
DK152224C (da) | 1988-06-27 |
JPS5938324A (ja) | 1984-03-02 |
DE3231540A1 (de) | 1984-03-01 |
ES525120A0 (es) | 1984-05-16 |
DK385283A (da) | 1984-02-26 |
ES8405084A1 (es) | 1984-05-16 |
TR21551A (tr) | 1984-09-27 |
BR8304569A (pt) | 1984-04-03 |
IL69419A0 (en) | 1983-11-30 |
IL69419A (en) | 1987-01-30 |
DE3362793D1 (en) | 1986-05-07 |
ATE18921T1 (de) | 1986-04-15 |
DK385283D0 (da) | 1983-08-23 |
DK152224B (da) | 1988-02-08 |
JPH0453925B2 (fr) | 1992-08-28 |
EP0103717A1 (fr) | 1984-03-28 |
YU153383A (en) | 1985-12-31 |
IN160848B (fr) | 1987-08-08 |
ZA835229B (en) | 1984-03-28 |
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