SE190842C1

SE190842C1 -

Info

Publication number: SE190842C1
Authority: SE
Publication date: 1964-01-01

Description

KLASS INTERNATIONELLSVENSK C 23 b48 a:14/01 PATENT- OCH REGISTRERINGSVERKET Ans. 1833/1956 inkom den 25/2 1956 utlagd den 25/11 1963 DANSK INDUSTRI SYNDIKAT Cm MADSEN A/S, KOPENHAMN, DANMARK Forfarande for varmebehandling av den hardforkromade insidan pa pipan till skjutvapen TJppfinnare: J Claces Foreliggande uppfinning avser ett formarande for varmebehandling av den hardforkromade insidan pa pipan till skjutvapen av alla slag. Forfarandet är speciellt lampat fOr varmebehandling av stalpipor till kulsprutepistoler, kulsprutegevar, automatkanoner och. andra automatskjutvapen. CLASS INTERNATIONAL SWEDISH C 23 b48 a: 14/01 PATENT AND REGISTRATION AGENCY Ans. 1833/1956 received on 25/2 1956 issued on 25/11 1963 DANSK INDUSTRI SYNDIKAT Cm MADSEN A / S, COPENHAGEN, DENMARK Procedure for heat treatment of the hard chrome-plated inside of the barrel for firearms Type inventor: J Claces The present invention relates to a forming for the hard chrome-plated inside of the barrel for firearms of all kinds. The procedure is specially designed for heat treatment of steel barrels for machine guns, machine guns, automatic cannons and. other automatic firearms.

Forsiik att forkroma pipor till skjutvapen invandigt for att pa sa satt forlanga deras livslangd har stott pa den svarigheten, att det elektrolytiskt utfallda, vatehaltiga kromskiktet pa grund av sin utomordentliga hardhet och sprodhet latt rives loss och skalas av fran silt underlag under skjutningen, varfor det ocksa vid fors& visat sig, att man vid en hardfOrkromning icke uppnar en Wining av pipornas. livslangd icke heller nar de forkromade piporna f5re skjutningen uppvarmes till ett par hundra grader Celsius for att eliminera sa kallad vatesprodhet. Attempts to chrome-plated barrels for firearms internally in order to prolong their service life have been based on the responsibility that the electrolytically precipitated, aqueous chromium layer, due to its extraordinary hardness and brittleness, can be torn off and peeled off from the silt surface during firing. It has also been shown that in the case of hard chrome plating, a Wining of the pipes is not achieved. longevity also not when the chrome-plated pipes before firing are heated to a couple of hundred degrees Celsius to eliminate so-called vadesprudhet.

Denna olagenhet vid hardforkromning är kand fran manga omra.den Mom tekniken, ]ml. a. vid cylindrar i forbranningsmotorer, dar man fOrslikt 15sa problemet genom att framstadia ett porost kromskikt, som pa olika satt, huvudsakligen pa kemisk va.g, forsetts med porer, som skola kunna upptaga smiirjoljan. This inertia in hard chromium plating is known from many areas. The Mom technique,] ml. a. in the case of cylinders in internal combustion engines, where the problem is reconciled by producing a porous chromium layer, which in various ways, mainly chemically, is continued with pores, which should be able to absorb the lubricating oil.

Detta forfaringssatt ar dock oanvandbart i skjutvapen, dar smorjning av loppen är omojlig. However, this procedure is unusable in firearms, where lubrication of the barrels is impossible.

Dessa brister avhjalpas genom forfarandet enligt uppfinningen, som i huvudsak .kannetecknas darav, att pipans hmeryta saint char-pa pa elektrolytisk vag anhragt kromskikt uppvarmes till en temperatur mellan 500 och 800° G. These shortcomings are remedied by the process according to the invention, which is mainly characterized by the fact that the hot surface of the barrel on the electrolytically vague applied chromium layer is heated to a temperature between 500 and 800 ° G.

Vid den ofta anvanda uppvarmningen av elektrolytiskt forkromade metallforemal, exempelvis jam- eller stalforemal, till en temperatur av omkring 200 till 400° C avlagsnas Dupl. kl. 48 a: 6/04 en del av det vate, som finnes i kromskiktet, varvid detta skikt mister en stor del av sin sprodhet och endast .obetydligt av sin hardhet, men andringen av egenskaperna ar icke sadan, att den hindrar att kromskiktet, exempelvis vid skjutning, avrives. In the frequently used heating of electrolytically chromed metal formals, for example jam or steel formals, to a temperature of about 200 to 400 ° C, Dupl is deposited. at 48 a: 6/04 a part of the water present in the chromium layer, this layer losing a large part of its brittleness and only insignificant of its hardness, but the change in the properties is not such that it prevents the chromium layer, e.g. when shooting, torn off.

Uppyarmer man till en hogre temperatur an 800 till 1000° C riskerar man att en mycket hard och sprod intermetallisk forening mellan Cr och Fe, som vanligen hetecknas som O-fas, uppstar i gra.nsskiktet mellan kromen och stalet eller jarnet. Denna forening gOr gransskiktet skort och medfor att kromskiktet vid skjutning eller annan kraftig mekanisk paverkan snabbt lossrives. iT.Jppvarmes daremot till en temperatur i intervallet 500° C-800° C blir kromskiktet segare och mjukare och haftar utmarkt vid metallunderlaget, exerapelvis jarn eller stal. Detta visar sig genom att kromskiktet icke langre avrives under skjutning. Samtidigt uppnas en betydande fOrbattring av pipans livslangd I forhallande till en motsvarande icke forkromad pipa. If heated to a higher temperature of 800 to 1000 ° C, there is a risk that a very hard and brittle intermetallic compound between Cr and Fe, which is usually referred to as O-phase, arises in the boundary layer between the chromium and the steel or iron. This association shortens the spruce layer and causes the chromium layer to be quickly torn off during firing or other strong mechanical impact. On the other hand, it is heated to a temperature in the range 500 ° C-800 ° C, the chrome layer becomes tougher and softer and adheres excellently to the metal substrate, for example iron or steel. This is shown by the fact that the chrome layer is no longer torn off during firing. At the same time, a significant improvement in the life of the barrel is achieved in relation to a corresponding non-chrome-plated barrel.

Detta kan mojligen forklaras genom 1) att hanvisa till, att det med stigande temperatur sker en minskning av kromskiktets hardhet och en okning av dess seghet och 2) genom att a:ntaga, att det i granszonen sker en diffusion av Fe in i kromskiktet respektive av Cr in i jarnet i(stalet), varvid kristalltypen pa bagge sidor om gransytan helt sakert joke andras, men de fysikaliska egenskaperna hos gransskikten, icke minst varmeutvidgningskoefficienterna, bli mindre avvikande. Samtidigt forhattras adhesionen Indian dem. De tva skikten haftar till foljd darav val samman, till och med under de snabba temperaturforandringarna i en pipa under skjutning, och det sega kromskiktet är hela tiden till- 2— — rackligt hart for att ge stor bestandighet vid slitning. This can possibly be explained by 1) referring to the fact that with increasing temperature there is a decrease in the hardness of the chromium layer and an increase in its toughness and 2) by assuming that in the spruce zone there is a diffusion of Fe into the chromium layer and of Cr into the iron in (the steel), whereby the type of crystal on the back sides of the spruce surface completely jokes, but the physical properties of the spruce layers, not least the coefficients of thermal expansion, become less deviant. At the same time, the adhesion Indian hates them. As a result, the two layers have choices together, even during the rapid temperature changes in a pipe during firing, and the tough chrome layer is always sufficiently hard to give great resistance to wear.

Denna forklaring gOr det uppenbart, att det enligt uppfinningen varmebehandlade kromskiktet far Overraskande egenartade egenskaper i jamforelse med normala kromskikt, varvid egenskaperna forbattras starkt under kraftpakanningar, icke minst temperaturandringar. This explanation makes it clear that the heat-treated chromium layer according to the invention acquires Surprisingly peculiar properties in comparison with normal chromium layers, the properties being greatly improved during force packings, not least temperature changes.

Utan varmebehandlingen enligt uppfinningen skalas kromskiktet under sadana forhallanden snabbt av, men efter denna varmebehandling far exempelvis en gevarspipa en mycket forhojd livslangd. Without the heat treatment according to the invention, the chromium layer is peeled off quickly under such conditions, but after this heat treatment, for example, a danger pipe has a much increased service life.

Awn efter langvariga skjutningar haftar kromskiktet standigt vid gevarspipan, aven da denna deformeras pa grund av uppvarmningen till hoga temperaturer. After prolonged firing, the chromium layer adheres permanently to the rifle barrel, even when it is deformed due to the heating to high temperatures.

Claims

1. Patent claim: Procedure for heat treatment of the hard chrome-plated inside of the barrel for firearms of all kinds, characterized in that the inner surface of the barrel and a crimp layer applied to the electrolytic scale are heated to a temperature between 500 and 800 ° C. Request publications: Patent documents from France 626,323; Germany 557,483; USA 2,402,834, 2,462,615.