US1326775A - Gabeiel van oobdt - Google Patents

Description

UNI ED STATES PATENT cur os.

GABRIEL VAN. oomrr, or BASEL, SWITZERLAND, assrsnon T socm'rn mourns nns usnvns GIULINI, or BASEL, swrrznnnnnn.

rnocnss 1m mcnnasmo THE nnmmnssann TEN-ACITY or METALS AND THE EASE a or THEIR wonxms wrrncur'rme-roonsi a p. 1,326,77 Specification of Letters Patent. Pate ted D 1919. no Drawing. Application filed April 30, 1919., Serial m. 293,883. To all whom it may concern: a a low or ahigh temperature'and b d- Be it known that I, GABRIEL VAN OORDT, ually raising or lowering the temperature Phil. Dr., a subject or the Queen. of the can ascertain that at which hardness is most- Netherlands, and resident of Basel, Switzerrapidly a'cquired. If the hardening experi- '5 land, have invented a new and useful Process ,ments for finding out the most advantageous for Increasing the Hardness and Tenacity hardening temperature of a metal are ex- -of Metals and the Easeof Their 'Working tended over a sufficiently long time, that i o with Cutting-Tools, of which the following say, over about several weeks, the results obis a full, clear, and exact specification. tained will show which is the highest hard- 10 It is-known that the properties of metals ness obtainable for the metal in question. which are technically important can be in-. =By varying the temperatures, there is then fi-uenced profoundly by heating the metal to determined the temperature at which this a high temperature. maximum hardness is the most quickly at- The principle underlying the present intained. This temperature is that which is 15 vention differs from that underlying the termed the characteristic heat hardening known processes for increasing the hardness temperature. 7 r and tenacity of metals and the ease of their The object of the invention may, however,

working with cutting toolsthat by the inalso be attained by heating the metal at a vention metals and alloys, particularly temperature below the characteristic heat 20 aluminium and aluminium alloys are heated, hardeniug temperature until the desired not to high temperatures, but to relatively hardness has been attained. If the temperalow temperatures, which are below the charture used is not fanbelow the characteristic a'cteristic annealing temperatures of the heat hardening temperature, it is generally metal in question 3 that is to say the possible by longer heating to obtain the i '25 temperatures used for the annealing by heat maximum hardness of the metal in question. treatment. The temperature to be usedat ,At still lower temperatures, however, this whicha hardness and a tenacity as great as maximum hardness is no longer obtainable possible are obtained in the shortest time is but only a hardness smaller than the said another for each metal or alloy, but'an en-; maximum hardness. The hardnesses attain- 30 tirely determined one. This temperature able are to a certain extent proportional to may be called the characteristic heat hardenthe decrease of the hardening temperatures. ing temperature and is ascertained experi- By a modification of the invention, therementally. a fore, there is produced only a partial harden- By the inve tion metals which are worked ing; This is sufiicient when,.for example, the i with difficulty on the lathe are converted in main object is to obtain a satisfactoryv metal .a short time'into metals which' can be satisfor turning or similar working and not a factorily turned and have high tenacity and metal having the. maximum hardness and hardness. By heating to a relatively low tenacity. In such a case the metal part to be temperature there is obtained inthe metal, hardened may, immediately after casting or 40 in a very short time, a stable structural reheating in a liquid bath, be brought into a 2 equilibrium for'the' limits of the usual temsoaking pit or soaking box, which by the peratures at which the metal is used. heat contained in the metal part is brought y The temperature of the heating is. ascer- -to.'a certain temperature below the charactained experimentally by subjecting the teristic heat hardening temperature; in this 45 metal for a period of several days toa conpit or box the metal part is left to acquire V stant temperature and then making hardness the desired hardening. The advantage 0 tests at room temperature which clearly this form of the invention is that fuel which show; whether hardening or softening has must be used for the complete heat hardenoccurred. Accordingt the indication thus ing, can be economized. At the low tem- 60 obtained a further experiment at another, peratures used it may not be necessary to higher, temperature is undertaken and anprotect the metal during heat treatment 7 other hardness test made. By the systematic from atmospheric air by using an indifferent 106 choice of temperatures, one can start from atmosphere or a packing.

. carried complet possible soft Y wheels, in

coolin the ot he teeth, will be er modification of the invention may be interrupted ing for the interpo sition-of a Working operation may be several times repeated and the heating ely or' in part to a finish. or example a screw thread may be cut on he preliminarily hardened metal when the ard sufiicient ening by strongly heating the worked surface may be recti subsequent finishing hardening.

partial hardening of metalstance the hardening of the teet ly performed mg the p tion, such to the characteristic h arts, for inof toothed by bring hardening temperature, but bel g when operating on sma her parts. The'parts close'to thoseto rdened will then have the low tem erature at which in'the, same period thehlgher or maximum hardness is not attained, so that the hardened parts, for instance the the rest.

harder than 1e metals to employ for toothed Wheels ,theselatter and to the tenacity necessary for p wheel towa to cool slowly. i Y;

11g examples illustrate'jthe inardening of the n for instance be ardening temperatura' e through the middle part of. th rd the whe 11 every case, rom the heat hardening tem perature to the ure has The tone vention: 7

Example'l: nsisting of 8 c the maximum Brinell 2.6, the piece while it is stll warm, after having healed at 530 to 550 C. if it was previously sub ected to a mechamcalworkin g in a cold.

condition, is left for four to five days at a his manner the y a Brinell hard ng of the metalbeen cast or anhe small wear of e toothed el shaft, which morej treatment at cent.

The characteristic ature of 70 C. of th exa c all mple was determine manner I the Testrace he.

its maximum is to say ness.

If after casting a mechanical wor or 530. the

Bri

worded the its call perature,; producing thus a gof-h such This tabular alloy of ,85

hardening th tility andcould umln'ium and 15 cool according of 10 mm. of kg. show e'ss of 50 d ach of the four foll . Brinell hard ness (P Temperure.

per cent. of cent; of

days. i s to 92 per cent. 0

ammering, to 550 foll owed by air had to take hardening ness. of 50 efore its nell hard turning rah e all ease y by rolling,

ardness an with cuttl a mechanical work e varia zinc attains hardness by the allo king, as rol an annealin ng tools; I

diameter ed for th egrees Brinell. cooling.

subjected temperatures,' as for inat 40 C B it exhibit show 0y .had further be dness amounts to 80-90 per ay. The

heat hardening temperoy employed in this (I in the following with cutting tools. eningto 92.6-B

piece and plece N0. 4

pieces cooled to room ected in every case to tions of'the hard pieces are shown in owing tabular exhibit: f w

150 kg. and 'D=10 mm.) er- I 5 clearly that an uminium and 15. the most treating i e increase .650=42.6

y wa

g of the metal at cool place befo and a test 80 e alloy the .measured Four pieces of to heat treat- No.2 at

ents were interrupted frequi t at 70 of hard Brinell that s subjected to ing, drawing.

1I1g'.dOWI1 in re its heat he alloy showing a ould diflicultly be After its hardrmell it could asily as I not lost its ducf be turnedon l brass. 'After is necessarythat s after the heat 11.01 the in tial hardhardening be efiected at a temperature 'below 70 C. that is to say below. the character- .istic heat hardening temperature and itis therefore convenient to cool'the metal fre- 6 quently during the mechanical working.

Example 2: Brinell hardness of 55.3 a piece of alloy c011 sisting of 98 per cent. aluminium an 2 per cent. copper, While it is still warm after cast vingor annealing, about 160 (3.,

air as described in Example 1.

in air or with exclusion of By this treatment the hardness of this alloy is in creased by about 70 per cent., hardness having been 32.7 degrees The following tabular exhibit shows how the characteristic ture was determined: v

the initial alteratiii'e.

hardness of 39.0 is attained, which is an, in-;

crease of hardness of about 10 per cent. of

' that of the unhardened zinc.

Example 4:: Pure copper having aBrinell hardness of 30 acquires perature of about 200 (3., the increase 0 hardness being about 40 percent.

-heat'hardening temperature of 200 C. ref

u "suited 'from theex eriments shown in, the

following tabular ex ibitz; 1

-. 'lest-piec'e Tempcr- Y No. ature.

hams days. ays. days. days. days.

In 5 days the Brinellhard Example 5 ness of bronze of-Lthe composition .94 per cent. tin 15 increased cent. copper and 6 per For attaining the highest is warmed for 10 days to I Brinell.

heat hardening tempera Templar;

and its alloys, with (1, this temperai the highest Brinell hardness of 42.9 in 20 days at a tern f 25 -days produced themaximu'm Brinell hardness of 55.3 degrees. (Tliecharacteristicheat The determination of Y the. characteristic 7 "Example 10: Pure zinc atv about 200 C. yielded the maximum Brinell hardness of 1 0 per cent. The like heat treatment for I I Bflmll hardness-(P lm kg. and D=10 I '2 mmdaiw mess of 0 per cent. or 37.8 Brinell hardness.

'300 0;). Example 12: Heating at 260 C. for 10 to 65.5 by heating at a temperature of 500 C.

The increase oihardness is about 12 per cent.

Example 6: Heating brass of the composition 72 per cent. copper and 28 percent.

zinc at about 300 C. for 8 days, increases the Brinellhardness to 47.4, that is'to say about 15 per cent.

' Example 7: A soft iron haying a Brine-ll hardness 85.7 hasthis hardness increased to 104 by a heating for about 50 days at 300 C. The heating should be conducted in an indifferent atmosphere or in a packing or in some other manner excluding air. The increase of hardness amounts to 21 'per cent.

After 10.days the hardness was 92.6 and after l5'days The following tabular exhibit shows how 1 the]. characteristic heat ture of 300 C. has'been determined: Banal hardnegm(-150 kg. new

100 on the same scale.

hardening tempera- Erin ell hardness (13 150 lrgfand D=1O mm.)

y .aftere Example 8: Metal parts consisting of per cent. aluminium and 15 percent. zinc were warmed at about 40 C. for 4 days and thereby attained Brinell hardness of 7 4.11 corresponding with. an increase of hardness of 56 per, cent. '10 days heating at the same temperature raised the hardness to 8 5.7 Brinell, an increase of 80 per cent, and this was the maximum result of this particular heat. hardening (the characteristic heat hardening temperature isabout 70 (1.).

- Example-9: A piece of metal consisting per cent. aluminium and 2 per cent. copper attainsa Brinell hardness of 42.9 when heated for. 10 days at about 120 C. corresponding with an increase of hardness of about 28 per cent. The like treatment for hardening temperature is about 160 C.)

heated for 2 days of 39, an increase of hardness 20 hours only produced an increase of hard- (The characteristic heat hardeningtempera- G. a brass consisting to a Brinell hardthe increase of hardness about 5 per cent. (The characteristic' heat hardening temperature is about days increases the hardness of soft iron by tools, consisting in heating the metal'to its about per cent. (The characteristic heat characteristic heat hardening temperature or hardening temperature is about 300 0.). to a temperature below this characteristic The heat hardening treatment may be apheat hardening temperature until the desired 5 plied to the finished product or maybe 1nhardness has been attained. 4

,terposed intelligently between the stages of 4. The herein described process for in working of the process to Which the metal is creasing the hardness, and tenacity of metals subjected. The heat hardening however, and the ease of their working w th cutting cannot be followed by any mechanical worktools, consisting in heating the metal to its 19 ing by means of presses, rollers, hammers or characteristic heat hardening temperature or the like at temperatures higher than the to a temperature below this characteristic characteristic heat hardening temperature; heat hardening temperature, interrupting 0n the other hand permissible cold working the heat hardening before the attainment of by means of presses, rollers, hammers, drawthe final condition, then working the metal is ings etc. produces a further increase of hardwith a cutting tool and then continuing the ness, tenacity and ease of Working with cutheat hardening until the desired ormaxiting tool. mum hardness has been attained. I V

What I claim is: 5. The herein described process for in- 1. The herein described process for increasingthe hardness, and tenacity ofmetalv 2c creasing the hardness, and tenacity'of metals articles and the ease of their Working with and the ease of their working with cutting cutting tools, consisting in' heating certain tools, consisting in heating the metal to a parts of the article to the characteristic heat relatively low temperature which is below hardening temperature or a temperaturethe characteristic temperature for the annear the said heat hardening temperature,

25 nealing of the metal in question. but below it, while the other parts of the ar- 2. The herein described process for in- .ticle are kept at a lower temperature, until creasing the hardness of aluminium and the parts to be hardened have attained. the aluminium alloys having a preponderating maximum or desired hardness. aluminium content, which consists in heat- 7 In Witness WhereofIhave hereunto signed y 30 ing the metal or alloy at-a temperature bemy name this 14th-day of April, 1919, in the tween and 200 C. until maximum hardpresence of two subscribing Witnesses. ness is attained. DR. GABRIEL VAN OORDT.

3. The herein described process for in Witnesses creasingthe hardness, and tenacity of metals 3 SOo'rr TAGGART, 35 and the ease of their Working with cutting I Armani) BRAM.