DE1508373B1 - Quenching baths for the remuneration of metallic materials - Google Patents

Description

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The present invention relates to novel quenching salts of these acids. In addition, it is used for tempering metallic materials. These polymers are also made of other comon-For tempering metallic materials, these mers will be built up which, as is not known, contribute to water solubility at temperatures between 750 and, for example, from acrylic acid esters and vinyl 125O ⁰ C and then either heated with air or 5 esters. Among the copolymers, block polymers are mostly quenched with a liquid, with merizates with strongly hydrophilic outer blocks, i.e. hardening of the material. z. B. copolymers of 50 to 80% acrylamide and since the use of pure water as a quenching 46 to 16% ammonium acrylate as a central block with stamittel in many cases with the disadvantage of faster tistischer distribution of the comonomers and 2% each and sudden cooling and thus the Danger of polyvinyl sulfonic acid as end blocks. All of these polyso-so-called hardness cracking is connected, one took merisate as well as their production are known or the deterrence hitherto mostly with the help of high-principle known.

boiling mineral oils. But also this method. The inventive effect of these polymers

ren is unsatisfactory in several respects because it is not recognizable depending on their molecular nature Oil can ignite because it is weighted by the hot metal 15, but can be a lower limit for this

with the development of gaseous decomposition pro-value, which is a minimum viscosity

products is cracked and because the resulting sity of 25 cP of a 1% aqueous solution

Carbon often corresponds to 25 ° C during subsequent tempering.

undesirably superficial to a boiling In addition to the polymers mentioned, the ment of the metal. This also uses up quenching baths that are set to pH values between 5 and 14 relatively expensive oil very quickly, and eventually all other auxiliary materials such as freezing are required there are additional work steps as well as device protection agents, wetting agents and anti-corrosion agents tings to wash off the oil again. contain.

Since one generally prefers the deterrent with the application of the new quenching baths with the help would make of aqueous baths, has no particular restrictions and equals 35 always tries to change the aqueous baths by additives so in the rest of the process engineering, which for the bisabzuänder, that she is known in the pure deterrent baths.

effect - characterized by a constant comparison The same applies to the materials to be tempered,

run the cooling function of temperature and being primarily all quenched and tempered steels, however Time - which are also well-suited for this property, including hardenable materials.

Oil baths. So have z. B. aqueous Since the concentration of the invention in the

Solutions of polyvinyl alcohol as usable baths contained polymer are very low anyway

grasslands. However, their use is also completely satisfactory, so there is no need for more precise regulations. in the

These baths do not, since their polyvinyl alcohol content is generally used, for example, in the case of Vermeistens must be uneconomically high and because of this, special steel (marked for example by

which the risk of hardening cracking does not have a sufficient content of 0.6% C, 0.25% Si and 0.65% Mn)

is low. the upper and alloyed tool steels (

Furthermore, from US Pat. No. 2,600,290, which is characterized, for example, by a content of

Use of aqueous solutions or aqueous dis- 0.35% C, 1.0% Si, 0.3% Mn or 1.1% Cr, 0.2% V, persions of polymers as quenching baths are 40 2.0% W) at the lower concentration limits.

knows. The polymers used are polyvinyl esters, such as beiten.

Polyvinyl acetate, as well as copolymers based on it, should be emphasized in addition to the very reduced

of vinyl esters, styrene, acrylic acid esters, acrylonitrile, risk of hardening cracks and the economy of the baths

Vinyl halides, maleic anhydride, vinylidene - also the fact that workpieces are also compli-

called chloride and ethylene. Furthermore, the ornamental shape can be perfectly deterred. A

also aqueous solutions or dispersions of poly- Another advantage of the new baths is that the

vinyl alcohol, from partially hydrolyzed polyvinyl- quench rate from bath temperature

esters and is clearly dependent on reaction products of the polyvinyl, so that the optimal

alcohol with compounds containing esters or acetals len speeds can be set, form, use as quenching baths. 50

These solutions also have the ones given above

insufficient effectiveness. example

The present invention was therefore the task

based on the technique of tempering metallic In an aqueous quenching bath, the 0.05% (GeWerkstoffe by hardening to better acting and 55 weight percent as in the following) of a more economical copolymerized aqueous quenching baths from 52% acrylamide, 45% ammonium acrylate and iron. 1.5% each of sodium vinyl sulfonate as outer blocks. It was found that aqueous baths, which contained through (p = 30) and a corrosion inhibitor, had a content of 0.01 to 1.0 percent by weight

water-soluble polymer, which is at least 60 a) an alloyed tool steel with 2.1% C and

ρ = 5 percent by weight of carbonamide groups, 12% Cr from 960 to 6O ⁰ C and

are marked, excellent for this purpose b) a stainless forged steel with 0.4 to

are suitable. 0.5% C and 13% Cr from 1000 to 6O ⁰ C

As defined polymers come in quenched.

primarily polyacrylamide (ρ = 62%), polymeth- 65 The hardnesses achieved are 63 HRC after a)

acrylamide and copolymers of acrylamide and DIN 50163 and for b) 627 kp / mm ² (test method:

Methacrylamides with acrylic acid, methacrylic acid, Ma- HV 0.5 according to DIN 50133) and corresponding values that

Flaic acid, vinyl sulfonic acid and alkali and ammonia can otherwise only be achieved with oils.

Claims (1)

Claim: Quenching baths for quenching and tempering metallic materials by hardening based on an aqueous solution of water-soluble polymers, characterized in that the baths contain 0.01 to 1.0% of such a polymer which contains at least ρ - 5% by weight of carbonamide groups.