DE691623C - Process to prevent scaling of parts to be hardened - Google Patents
Process to prevent scaling of parts to be hardenedInfo
- Publication number
- DE691623C DE691623C DE1937M0138984 DEM0138984D DE691623C DE 691623 C DE691623 C DE 691623C DE 1937M0138984 DE1937M0138984 DE 1937M0138984 DE M0138984 D DEM0138984 D DE M0138984D DE 691623 C DE691623 C DE 691623C
- Authority
- DE
- Germany
- Prior art keywords
- parts
- hardened
- prevent scaling
- scaling
- steel
- 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
- C21D1/68—Temporary coatings or embedding materials applied before or during heat treatment
- C21D1/70—Temporary coatings or embedding materials applied before or during heat treatment while heating or quenching
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)
- Chemical Treatment Of Metals (AREA)
Description
Verfahren zur Verhinderung der Verzunderung von zu härtenden Teilen Es ist bekannt, daß die Oberfläche von Stahl,gegenst'a'nden, die, einer Härtun,gsbehandhing unterzogen weren, mehr oder minder stark verzundert.Process to prevent scaling of parts to be hardened It is known that the surface of steel objects that have been subjected to hardening were subjected to more or less strong scaling.
Die Zunderbildumg tritt während des Erhitzens sowie auch in dem Augenblick, in dem die Gegenstände vom Ofen rotglühend in das Abschreckbad. gebracht werden bzw. während des Abkühlens, ein. Als Folge dieser Verzunderung muß die Zunderschichtentfernt werden. Die Entfernung des Zunders bringt mannigfache Schwierigkeiten mit sich. Beispielsweise lassen sich Vertiefungen, Hohlräume, Falzen nur unvollkommen entzundern. Ferner werden durch den Säureangriff der Beize die Abmessungen der Werkstücke verändert. Außerdem tritt infolge der Wasserstoffaufnahme die unter der Bezeichnung Beizbrüchigkeit bekannte Verschlechterung des Stahls auf.The scale formation occurs during heating as well as at the moment in which the objects from the furnace red-hot in the quenching bath. to be brought or while it cools down. As a result of this scaling, the scale layer must be removed will. The removal of the scale presents various difficulties. For example, depressions, cavities and folds can only be descaled incompletely. Furthermore, the acid attack of the stain changes the dimensions of the workpieces. In addition, as a result of the uptake of hydrogen, what is known as pickling brittleness occurs known deterioration in steel.
Man hat nun versucht, durch Aufstreichen von verschiedenartigen Überzügen und Schutzpasten auf die zu härtenden Gegenstände" diese während der eigentlichen Glühung und während des Abschrecke'ns hzw. Abkühlens vor Oxydation zu schützen. Als solche Mittel sind beispielsweise Mischungen von Salz-und Hufmehl, vom Wachs oder öl mit Blutl.augensalz, von Petroleum und Cyankali usw. vorgeschlagen worden.Attempts have now been made by spreading various types of coatings and protective pastes on the objects to be hardened "this during the actual Annealing and during the deterrent Protect from oxidation during cooling. Such agents are, for example, mixtures of salt and hoof meal, made from wax or oil with blood eye salt, petroleum and cyanide, etc. have been suggested.
Nach vorliegender Erfindung werden die zu härtenden Stahlwerkstücke nach bekannten Verfahren auf chemischem Wege mit einer auf der Stahloberfläche fesithaftenden Schicht von Metallphosphaten überzogen. Auf solche Weise vorbehandelte und geschützte Teile zeigen eine nur so geringe Veränderung der Oberfläche, daß ein achträ,gliches E'ntzundern sich erübrigt. Da bekannt ist, daß Phosphatschichten nicht hitzebeständig sind, war dieses Ergebnis nicht zu-erwarten. Das beschriebene Verfahren hat den weiteren Vorteil gegenüber Schutzpasten, daß bei Teilen mit kleinsten Abmessungen und bei Teilen mit Vertiefungen, Hohlräume usw. die ge- samte Oberfläche während des Härtevorgangs gleichmäßig vor dem Verzundern geschützt. wird.According to the present invention, the steel workpieces to be hardened are chemically coated by known methods with a layer of metal phosphates adhering to the steel surface. Parts pretreated and protected in this way show only such a slight change in the surface that an eighth, similar descaling is not necessary. Since it is known that phosphate layers are not heat-resistant, this result was not to be expected. The method described has the further advantage over protection pastes, etc. that uniformly protected entire surface during the hardening process for parts with very small dimensions, and for parts with depressions, cavities before scaling. will.
Claims (1)
Priority Applications (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE1937M0138984 DE691623C (en) | 1937-08-20 | 1937-08-20 | Process to prevent scaling of parts to be hardened |
Applications Claiming Priority (1)
Application Number | Priority Date | Filing Date | Title |
---|---|---|---|
DE1937M0138984 DE691623C (en) | 1937-08-20 | 1937-08-20 | Process to prevent scaling of parts to be hardened |
Publications (1)
Publication Number | Publication Date |
---|---|
DE691623C true DE691623C (en) | 1940-06-01 |
Family
ID=7334213
Family Applications (1)
Application Number | Title | Priority Date | Filing Date |
---|---|---|---|
DE1937M0138984 Expired DE691623C (en) | 1937-08-20 | 1937-08-20 | Process to prevent scaling of parts to be hardened |
Country Status (1)
Country | Link |
---|---|
DE (1) | DE691623C (en) |
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1030377B (en) * | 1955-06-04 | 1958-05-22 | Metallgesellschaft Ag | Method to prevent stacked sheets or coiled strips from sticking together during annealing |
DE1111480B (en) * | 1956-01-07 | 1961-07-20 | Metallgesellschaft Ag | Process to facilitate the cold deformation of heat-treated iron or steel workpieces |
-
1937
- 1937-08-20 DE DE1937M0138984 patent/DE691623C/en not_active Expired
Cited By (2)
Publication number | Priority date | Publication date | Assignee | Title |
---|---|---|---|---|
DE1030377B (en) * | 1955-06-04 | 1958-05-22 | Metallgesellschaft Ag | Method to prevent stacked sheets or coiled strips from sticking together during annealing |
DE1111480B (en) * | 1956-01-07 | 1961-07-20 | Metallgesellschaft Ag | Process to facilitate the cold deformation of heat-treated iron or steel workpieces |
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