EP3436615A2 - Pièce pour conduites de gaz ou d'eau - Google Patents

Pièce pour conduites de gaz ou d'eau

Info

Publication number
EP3436615A2
EP3436615A2 EP17718474.4A EP17718474A EP3436615A2 EP 3436615 A2 EP3436615 A2 EP 3436615A2 EP 17718474 A EP17718474 A EP 17718474A EP 3436615 A2 EP3436615 A2 EP 3436615A2
Authority
EP
European Patent Office
Prior art keywords
component according
alloy
lead
component
content
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.)
Withdrawn
Application number
EP17718474.4A
Other languages
German (de)
English (en)
Inventor
Martin Haake
Andreas Hansen
Frank Leistritz
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Geberit International AG
Gebr Kemper GmbH and Co KG
Rehau Automotive SE and Co KG
Original Assignee
Geberit International AG
Rehau AG and Co
Gebr Kemper GmbH and Co KG
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from DE202016101661.4U external-priority patent/DE202016101661U1/de
Application filed by Geberit International AG, Rehau AG and Co, Gebr Kemper GmbH and Co KG filed Critical Geberit International AG
Publication of EP3436615A2 publication Critical patent/EP3436615A2/fr
Withdrawn legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C22—METALLURGY; FERROUS OR NON-FERROUS ALLOYS; TREATMENT OF ALLOYS OR NON-FERROUS METALS
    • C22C—ALLOYS
    • C22C9/00—Alloys based on copper
    • C22C9/02—Alloys based on copper with tin as the next major constituent

Definitions

  • the present invention relates to a component for media-carrying gas or water pipes, in particular fitting or fitting for drinking water pipes, wherein the component consists at least partially of a lead-free copper alloy.
  • metallic materials for use in components for water-bearing especially drinking water leading trades, such as fittings, fittings, pipes, press connectors, roof gutters or gutters, special requirements must be met.
  • the corrosion resistance should be mentioned.
  • copper-containing non-ferrous metal alloys such as bronze, brass or gunmetal also contain a certain amount of lead, because lead has the
  • EP 1 798 298 A1 discloses a largely lead-free and nickel-free copper alloy which, in addition to copper and unavoidable impurities, contains 2% by weight to 4.5% by weight of silicon, 1% by weight to 15% by weight.
  • the alloy described in EP 1 798 298 A1 exhibits an improved migration behavior for lead, nickel, copper and zinc ions compared to a conventional gunmetal.
  • the alloy can be subjected to a heat treatment after casting in order to achieve a high proportion of ⁇ -mixed crystal and thus a particularly favorable migration behavior of the alloy.
  • CuSn5Zn5Pb2 with contents of about 5 wt% tin and about 5 wt% zinc is widely used.
  • This copper alloy has excellent corrosion resistance and can therefore be used in all water qualities within the drinking water supply. Alloys of this type are usually formed in the structure of a single phase and offer
  • CONFIRMATION COPY Her a high plastic deformability. However, it is precisely this plastic deformability that causes problems in machining machining. Single-phase copper materials tend to form a long chip. This type of chip inhibits the work flow during fully automated turning or drilling, and leads to heavy wear on the tool cutting edges. In order to be able to process the products nevertheless economically, lead is added to the alloys as a chip-breaking additive. Lead enables economical, fully automated mechanical processing.
  • Lead is practically insoluble in copper and has a low melting point. As a result, it is the last solidifying element in copper-tin alloys. This constitutional behavior leads to lead at the end of solidification in the microstructure in the form of evenly distributed, small, drop - shaped particles in between
  • Dendrite arms present. These fine, teardrop-shaped particles act as chipbreakers without affecting the original properties of the material. This is particularly evident in the corrosion resistance, since the lead particles are present as incoherent phases and thus can not interact with the surrounding matrix. Also, the uniform distribution of small, teardrop-shaped lead particles ensures that similar mechanical characteristics are consistently to be expected over a uniform cross section.
  • the present invention has the object to provide a lead-free copper alloy for the production of components for media-carrying gas or water pipes, compared to a conventional gunmetal alloy, such as CuSn5Zn5Pb2, a corrosion-resistant matrix, good strength properties with good handling properties, a high pressure tightness and improved migration behavior.
  • the lead-free copper alloy should have a good casting behavior, eg. In sand or continuous casting.
  • the lead-free copper alloy has improved corrosion resistance over the entire frame prescribed by the Drinking Water Ordinance (hereinafter referred to as "TWVO") Accordingly, the present invention preferably constitutes a component for media-carrying gas or water pipelines, particularly. in particular a fitting or a fitting for drinking water pipes, wherein the component consists at least partially of the lead-free copper alloy according to the invention.
  • the formed sulfides preferably as copper sulfide, offer the advantage, similar to the lead particles, of being present as incoherent phases.
  • the tin content has an influence on the strength, corrosion resistance and on the phase distribution and, in the claimed range from 3.5% by weight to ⁇ 4.8% by weight, achieves an optimally balanced, economical ratio of the properties described above. With a tin content of more than 4.8% by weight, the strength and corrosion resistance in the matrix continue to increase, but under normal cooling conditions in sand casting, the distribution of the sulfides becomes coarser and the size increases. At levels below 3.5% by weight of tin, there is insufficient corrosion inhibition. Also, because of the weak solid solution hardening necessary for the practice properties are not achieved.
  • the sulfur content of 0.25 wt .-% to 0.65 wt .-% determines the volume fraction of the sulfides with. From 0.25 wt .-% sulfur, an amount of sulfide particles is produced, which ensures sufficient machinability of the alloy. Sulfur content above 0.65 wt% sulfur can lead to the formation of undesirable coarse sulfide particles. In addition, due to the high proportion of sulfide particles, the load-transmitted cross section, ie the cross section of the component which absorbs stresses from the outside, can be reduced so much that a deterioration of the mechanical characteristics, such as elongation at break and the like, occurs.
  • the metal sulfides are present in such a sulfur content in the lead-free copper alloy as an incoherent, finely divided, disperse phase in the form of finely divided particles. This offers the advantage that any corrosion occurring only to a limited extent locally on these particles and not along coherent, larger, individual phases of the alloy structure takes place, as is the case, for example, with standard brass. Due to the small size of the particles no significant corrosive attack takes place.
  • the proportion of phosphorus (P) in the lead-free copper alloy according to the invention is 0.015 wt .-% to 0.1 wt .-%. Below 0.015% by weight of phosphorus, there is no sufficient deoxidation of the melt, which has a negative effect on the phase formation of the alloy. On the other hand, with a phosphorus content of more than 0.1% by weight, the lead-free copper alloy tends to adversely affect the mechanical properties, such as reduced elongation at break. From these viewpoints, the weight proportion of phosphorus in the lead-free copper alloy is preferably in the range of 0.02 wt% to 0.08 wt%, more preferably in the range of 0.04 wt% to 0.06 wt%. -%.
  • the term "lead-free copper alloy” means a copper alloy containing, in particular, lead as an unavoidable impurity in an amount of not more than 0.25 wt%, but preferably 0.09 wt%, more preferably not more than 0
  • the lead content is at most 0.25% by weight, preferably at most 0.09% by weight and particularly preferably at most less than or equal to 0.05% by weight
  • the alloy shows no signs of increased lead delivery in the first few weeks From the eighth week of testing, no significant lead migration is detected in the drinking water or lies within the range of the measuring accuracy of the method.
  • the low lead content in the alloy used in the invention thus leads to a significant reduction of metal ion migration in drinking water, the low lead content has no negative effects on the chip breaking and thus on the machinability of the alloy used in the invention.
  • the nickel content in the alloy used in the invention is at most 0.4 wt .-%, preferably, the nickel content is at most 0.3 wt .-%.
  • the addition of nickel increases the corrosion resistance of the alloy, without being in conflict with hygienic safety. Similar to lead, the values of nickel migration are far below the legally required limit when tested according to DIN EN 15664-1. Furthermore, it was found that an antimony content of at most 0.1% by weight with respect to the properties of the drinking water migration is not critical.
  • the alloy may furthermore have an iron content of at most 0.3% by weight.
  • the lead-free copper alloy may also contain fractions of the elements iron (Fe), zirconium (Zr) and / or boron (B) alone or in a combination of at least two of said elements as grain refiner. It is preferred that iron in a weight fraction of up to 0.3 wt .-%, zirconium in a weight fraction of up to 0.01 wt .-% and / or boron in a weight fraction of up to 0.01 wt. -% are contained in the lead-free copper alloy. Avoid the grain finer
  • the copper content of the lead-free copper alloy is at least 90% by weight, preferably more than 91% by weight.
  • the sulfides of the lead-free copper alloy are homogeneously distributed in the structure.
  • the number of sulfide particles should be high and their average size should be low in order to ensure uniform mechanical properties, good corrosion resistance, improved machinability and high pressure tightness over the entire microstructure.
  • copper sulfide is preferable. because the presence of copper sulphide allows to substitute the volume of lead with a much lower content of sulfur.
  • the component according to the invention at least in sections has a wall thickness in the range of 0.5 mm to 6.0 mm, since the thin wall thickness leads to suitable cooling rates for the formation of copper sulfides.
  • the entire component according to the invention has a wall thickness within the ranges of 0.5 mm to 4.0 mm, since a wall thickness in this range results in a particularly increased formation of the desired sulfide particles.
  • a wall thickness below 0.5 mm could not have sufficient mechanical strength of the component according to the invention due to the small cross section. From these points of view, it is preferred that the component according to the invention at least partially has a wall thickness in the range of 1, 0 mm to 4.0 mm.
  • At a wall thickness of less than 6 mm in the transverse section of the component according to the invention at least a proportion of 1, 6 area percent sulfide particles and / or a surface area factor ASP% is less than 1000.
  • Such values result in sulfur sulfides being present as an incoherent, finely divided, disperse phase.
  • deep trough and / or hole-shaped attacks, in particular corrosion attacks are avoided on the components according to the invention.
  • the term "Area Property Code ASP%" is the mathematical description for the measure of the shape and location of a bell curve, which is a plot of the averages of the area classes (abscissa) in combination with the percentage distribution of the area
  • Sulfide particles in these surface classes results (see Fig. 1).
  • the value of the surface content index ASP% is obtained by measuring the area of the respective particles, for example from an enlarged image of a micrograph, the percentage allocation of the particles detectable in the image in classes, the multiplication of the percentage values of the allocation with the mean value of the class and the formation of a large average from the resulting averages of the classes, with the large mean being taken as the "area key figure ASP%".
  • the alloy used in the invention has the excellent property of forming a topcoat very rapidly on the inner, water-wetted surface.
  • the cover layer has a thickness of preferably at least 2 ⁇ m, more preferably of at least 3 ⁇ , on. This covering layer increases the corrosion resistance and ensures the longevity of the components made of this material, since further corrosion is prevented. Migration from the material to the drinking water can only take place if corrosion processes take place in the material.
  • the top layer thus acts as a protective layer and limits the further metal delivery to the drinking water to a minimum.
  • the copper content in the described alloy is higher than in conventional gunmetal alloys, such. As CuSnZn5Pb2, only a reduced copper metal release takes place.
  • the term "component for media-carrying gas or drinking water lines" is to be understood in particular as those components which come into contact with a domestic installation pipe system with water, in particular with drinking water, whereby fitting and fittings of such domestic installation pipe systems are preferred according to the invention
  • a fitting is to be mentioned in particular the connection piece known from EP 2 250 421 A1.
  • Fig. 1 shows exemplary plots of the areas of the particles versus the percentage
  • Fig. 2 is an overview of the test waters in the diagram according to Turner;
  • 3 shows a diagram from which the attack depths of the dezincification in the standard brass in the hot aging test carried out emerge after 5 months of aging
  • 4 is an overview diagram showing the formation of the cover layer in the lead-free copper alloy used in the present invention after 5 months of aging;
  • FIG. 6 shows a photograph of the alloy 2 used according to the invention, which shows an example of a continuous covering layer in the hot aging test (based on Turner with a chloride content of 250 mg / l and a carbonate hardness of 5.5
  • Fig. 7 is a diagram of the thermal analysis of two melts with different zinc contents cast under the same conditions
  • Fig. 8 is a Ge Heilgeschliffsent a component of a melt, which was cast with a zinc content of about 3.9 wt .-%;
  • FIG. 9 is a Ge Schogeschliffsent a component according to the invention from a melt, which was cast with a zinc content of about 2.4 wt .-%; 10 is a Ge Schogeschliffsent a component according to the invention from a melt, which has been slowly cooled; and FIG. 11 shows a micrograph of a component according to the invention from a melt which has been cooled rapidly.
  • FIG. 2 shows a Turner diagram for the test waters used in the hot aging test.
  • the carbonate hardness (as a measure of water hardness) is plotted against the chloride ion content of the test water.
  • the line, labeled "Turner Classic”, represents the corrosion characteristic of dezincification developed by Turner ("The Influence of Water Composition on the Decini- zation of Duplex Brass Fittings", 1965). According to the usual interpretation of the world of corrosion, no dezincification takes place in the area below this line. Above this line, however, there is a very high risk that damage due to dezincification of the relevant component occurs.
  • the points shown give an overview of the different test waters that were used in the described hot swapping test.
  • test specimens For the production of test specimens, half cylinders with a wall thickness of 5 mm were cast from the alloys 1 and 2. Thereafter, the test specimens were on the outside by means of a turning to a roughness Rz of max. 25 ⁇ machined and on the inside by means of a drilling with a through hole roughness Rz of max. 40 pm provided.
  • This special surface treatment is intended to make it possible to compare the specimens with real components.
  • test specimens The surface of the specimens was cleaned with acetone. Subsequently, the test specimens were placed freely hanging in a test container. The test containers were then placed in a 90 ° C oven for five months with the test medium changed at seven-day intervals.
  • test media were each 21 different test water with different pH values and carbonate hardness (the carbonate hardness (KH) is the proportion of calcium and magnesium ions, for the unit volume in the equivalent concentration
  • test containers After completion of the five-month test period, the test containers are removed from the oven, cooled to room temperature, taken the test specimens from the respective test containers, dried, cut open and the cut surface is examined by appropriate optical microscopy.
  • Alloys 1 and 2 showed over the entire area of the drinking water ordinance tested in hot aging an outstanding formation of a protective, adherent, closed covering layer required for copper alloys which has a thickness of at least 2 ⁇ m in the hot aging test and thus an improved covering layer with respect to a conventional lead-containing copper alloy based on a CuSnZn alloy (eg CuSn5Zn5Pb). Furthermore, this layer is almost free of disturbances or defects and thus unfolds its full protection by avoiding a deeper, local corrosion attack (see FIG. 4 and FIG. 6).
  • the attack depths for standard brass (CuZn40Pb2) are shown after a five-month hot aging test for the respective test waters. In each case, a selective corrosion in the form of a dezincification, predominantly a zinc plating, appears. Clearly visible are attack depths, which in some cases suffice up to approx. 750 pm and thus illustrate a very poor corrosion resistance.
  • FIG. 4 shows the behavior of the cover layer formation of a lead-free copper alloy (alloy 1 and alloy 2) used according to the invention after a five-month hot aging test for the respective test waters. It turns out that it only comes to the formation of a protective topcoat. There is no visible selective corrosion attack. The thickness of the formed, adherent, protective cover layer is at least 4 pm.
  • Fig. 5 is a photograph of the microstructure in standard brass
  • FIG. 6 shows a photograph of the microstructure of a result of the five-month hot aging test, based on Turner, with a chloride content of 250 mg / l and a carbonate hardness of 5.5 ° dH, based on an alloy component according to the invention 2 (Alloy 1 shows an analogous behavior) was performed.
  • the component according to the invention shows no selective corrosion attack after an identical heat aging test but a uniform, homogeneous structure of a protective, firmly adhering cover layer with a thickness of 4 ⁇ m to 23 ⁇ m.
  • the alloy in the hot aging test carried out here is free from selective corrosion attacks (eg dezincification and stress corrosion cracking) and almost all other corrosion phenomena.
  • the experiments also show that sulfur sulfides as incoherent, finely divided, disperse phases show a significant corrosive advantage. This results from the avoidance of deep trough and / or hole-shaped attacks, which could lead to a significantly accelerated corrosion by a possible decrease in the pH and a concentration of the critical ingredients of the medium.
  • FIG. 7 shows a thermal analysis in a temperature-time diagram, by means of which thermal effects (for example release of latent heat) of metals can be detected which can arise in the case of solid-to-liquid transitions or solid state phase transformations.
  • thermal effects for example release of latent heat
  • Plotted is the cooling temperature of the alloy and the first time derivative of the measurement signal against the time, which is described as the cooling rate.
  • a change in the peak in the cooling rate curve corresponds to a thermal effect in the material.
  • sulfide formation should be aimed for shortly before the end of solidification at low temperature, since in this way the sulfides, like the lead, are distributed more homogeneously in the microstructure.
  • the cooling rate in Fig. 7 corresponds to the typical solidification process of a copper-tin alloy to 5 wt .-% tin in sand casting. Upon further comparison of the two curves it becomes clear that in the alloy 3 at approx. 400s an early thermal effect occurs during the proceeding solidification process, which results in a
  • Des shimmer was recognized that the cooling conditions of the melt to a component according to the invention, have an influence on the sulfide formation.
  • a high cooling rate which is preferred for a thin wall, results in a fine-meshed dendritic network with fine residual melt areas, from which a globular formation of the sulfides is supported.
  • rapid cooling is preferred according to the invention.
  • 10 and 11 show micrographs of components according to the invention from an identical melt which has been cooled under varying conditions. In a rapid cooling, the micrograph in Fig. 11 shows a structure resulting in higher mechanical characteristics, e.g. Tensile strength, elongation at break and the like results.
  • the alloys used according to the invention can be characterized by an area content index ASP% of less than 1000.

Abstract

La présente invention concerne une pièce pour conduites de gaz ou d'eau, en particulier un raccord ou un accessoire de robinetterie pour conduites d'eau potable, ladite pièce étant constituée au moins en partie d'un alliage de cuivre exempt de plomb qui contient les constituants suivants en % en poids : 3,5 % en poids ≤ Sn ≤ 4,8 % en poids; 1,5 % en poids ≤ Zn ≤ 3,5 % en poids ≤ P ≤ 0,1 % en poids; et les impuretés inévitable, le reste étant constitué de cuivre.
EP17718474.4A 2016-03-29 2017-03-28 Pièce pour conduites de gaz ou d'eau Withdrawn EP3436615A2 (fr)

Applications Claiming Priority (3)

Application Number Priority Date Filing Date Title
DE202016101661.4U DE202016101661U1 (de) 2016-03-29 2016-03-29 Bauteil für medienführende Gas- oder Wasserleitungen
EP2017151949 2017-01-18
PCT/EP2017/000374 WO2017167441A2 (fr) 2016-03-29 2017-03-28 Pièce pour conduites de gaz ou d'eau

Publications (1)

Publication Number Publication Date
EP3436615A2 true EP3436615A2 (fr) 2019-02-06

Family

ID=58579128

Family Applications (1)

Application Number Title Priority Date Filing Date
EP17718474.4A Withdrawn EP3436615A2 (fr) 2016-03-29 2017-03-28 Pièce pour conduites de gaz ou d'eau

Country Status (1)

Country Link
EP (1) EP3436615A2 (fr)

Similar Documents

Publication Publication Date Title
EP3225707B1 (fr) Composant pour des canalisations d'eau ou de gaz acheminant des milieux comprenant un alliage de cuivre
DE69835912T2 (de) Automatenlegierung auf Kupferbasis.
DE69838115T2 (de) Bleifreie Automatenkupferlegierung
EP1817438A1 (fr) Alliage de cuivre peu sensible aux migrations
AT509112B1 (de) Gleitschicht
AT522440B1 (de) Mehrschichtgleitlagerelement
EP2964798A1 (fr) Alliage cuivre-zinc pour une robinetterie sanitaire, et procédé de fabrication de ladite robinetterie
EP2742161B1 (fr) Alliage de cuivre zinc
DE10301552B3 (de) Korrosionsbeständige Messinglegierung für Trinkwasserformteile
EP3377663A1 (fr) Alliage de cuivre, nickel et zinc et son utilisation
EP3374533B1 (fr) Alliage de laiton à haute résistance et produit d'alliage de laiton à haute résistance
DE102012013817A1 (de) Formteile aus korrosionsbeständigen Kupferlegierungen
DE4233668C2 (de) Korrosionsfeste Legierung auf Kupferbasis
AT518875B1 (de) Mehrschichtgleitlagerelement
DE112014002690T5 (de) Kupferlegierung
WO1993024670A1 (fr) Alliage de laiton
EP3436615A2 (fr) Pièce pour conduites de gaz ou d'eau
EP1749897B1 (fr) Procédé de fabrication de pièces coulées en cuivre, dont la tendance de migration est réduite par recuit
WO2020182845A1 (fr) Procédé pour produire des éléments conçus pour des conduites de gaz ou d'eau transportant des substances, et élément produit au moyen de ce procédé
EP3938550A1 (fr) Procédé pour produire des éléments métalliques et élément métallique produit au moyen de ce procédé
EP0943695A1 (fr) Fil à base de zinc et d'aluminium et son usage en projection thermique comme protection contre la corrosion
EP2215286A1 (fr) Préparation d'éléments d'amenée d'eau à partir d'alliages de laiton à libération limitée d'ions métal
DE3626435A1 (de) Kupfer-zink-legierung
DE102018212942B4 (de) Verfahren zum Erzeugen einer Schmelze einer Kupfergusslegierung und Gussstück, hergestellt aus dieser Schmelze
EP3899073B1 (fr) Alliage cu-zn

Legal Events

Date Code Title Description
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: UNKNOWN

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE INTERNATIONAL PUBLICATION HAS BEEN MADE

PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: REQUEST FOR EXAMINATION WAS MADE

17P Request for examination filed

Effective date: 20181025

AK Designated contracting states

Kind code of ref document: A2

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: EXAMINATION IS IN PROGRESS

17Q First examination report despatched

Effective date: 20190910

STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20200603