摘要:
Undesired nitrites are formed during the treatment of salt bath nitrided structural components of iron and steel in nitrate containing cooling baths, and they must be removed from the washing water. The build-up of nitrites can be avoided by oxidizing the nitrite in the salt bath into nitrate by passing air into the cooling bath during off-times.
摘要:
Waste waters from salt bath hardening and galvanizing operations are removed through evaporation of the injurious material containing waste water and complete detoxification of the concentrate from the evaporation. The waste waters are first brought to a salt content of 300-500 grams/liter and this concentrated solution is then supplied to a molten salt bath.
摘要:
There is provided a boriding agent for mass produced parts of ferrous and non-ferrous metals consisting essentially of a boron yielding material, activator, filler and water as a binder and containing in the boriding agent 2 to 8 weight % of pyrogenic silica.
摘要:
Portions of the surface area of metal workpieces are insulated in thermochemical treatment by covering the areas with a self-adhering textile tape having metal powder embedded in its adhesive layer.
摘要:
To increase the corrosion resistance of nitrided structural parts made of iron materials which are useful for all types of iron and steel there is carried out an oxidation treatment in connection with the nitriding process. The oxidation treatment is carried out for 15 to 50 minutes in an oxidizing salt bath. The salt bath preferably consists of alkali hydroxides with 2 to 20% of alkali nitrates.
摘要:
Iron and steel construction parts which have been treated in a high cyanate, low cyanide or cyanide free nitriding salt bath or in other cyanide containing salt baths are tempered in a bath comprising an alkali metal hydroxide. There also can be present in the cooling bath 2 to 20 weight % of an alkali nitrate.
摘要:
Low cyanide nitriding salt baths which are composed of alkali cyanate and alkali carbonate and used for treating components made of steel and iron produce coatings on the surface of the component in some cases and can lead to problems in the use of the components. A satisfactory surface quality can be obtained from nitriding salt baths which additionally contain 0.5 to 100 ppm of selenium.
摘要:
The present invention relates to powdered boriding compositions for the production of single-phase boride layers on metal articles being substantially free from cracks in the case of mechanical stress, which comprise an activator and a mixture of a boron-releasing agent and an unreactive refractory material, such as silicon carbide.
摘要:
In order to improve the corrosion resistance, carbonitrided components formed of ferrous material are treated, after an oxidation treatment, with a solution of a heat hardenable organic synthetic resin and heat-treated at 80.degree. to 200.degree. C.