Global Patent Index - EP 0306810 B2

EP 0306810 B2 20000329 - Method of producing pitting-resistant hard drawn tubes made of copper or copper-based alloys

Title (en)

Method of producing pitting-resistant hard drawn tubes made of copper or copper-based alloys

Title (de)

Verfahren zur Herstellung lochfrassbeständiger hartgezogener Rohre aus Kupfer oder Kupferlegierungen

Title (fr)

Procédé pour la fabrication de tubes en cuivre ou en alliages cuivreux étirés à froid et résistant à la corrosion

Publication

EP 0306810 B2 20000329 (DE)

Application

EP 88114157 A 19880831

Priority

DE 3730367 A 19870910

Abstract (en)

[origin: EP0306810A2] The corrosion damage, particularly that due to local pitting, which occurs on hard-drawn copper tubes used in the sanitary sector is generally caused by carbon-containing films but also by oxide films. A carbon film on the inside of the tube is formed, for example, if the drawing compound added when drawing the tube is subjected to excessive heat. To avoid these damaging films and to improve the pitting resistance of hard tubes made of copper or copper-based alloys, the tubes are first of all degreased. In a further process step, the inner surface of the tubes is then treated with a blasting abrasive in order to establish a minimum roughness. A mean roughness of 0.8 to 1.0 mu m has proven particularly advantageous. The hard-drawn tubes treated by the method according to the invention have none of the films which promote pitting, even after brazing and/or hot bending.

IPC 1-7

B24C 3/32

IPC 8 full level

B24C 3/32 (2006.01)

CPC (source: EP)

B24C 3/327 (2013.01)

Designated contracting state (EPC)

AT BE CH DE ES FR GB GR IT LI LU NL SE

DOCDB simple family (publication)

EP 0306810 A2 19890315; EP 0306810 A3 19900530; EP 0306810 B1 19940323; EP 0306810 B2 20000329; AT 103225 T 19940415; DE 3730367 A1 19890323; DE 3730367 C2 19971009; DE 3888605 D1 19940428; DK 170250 B1 19950717; DK 493288 D0 19880905; DK 495488 A 19890311; DK 495488 D0 19880906; ES 2050684 T3 19940601; ES 2050684 T5 20000701; FI 884071 A0 19880902; FI 884071 A 19890311; FI 94496 B 19950615; GR 3033568 T3 20000929; IE 63028 B1 19950322; IE 882707 L 19890310; PL 163146 B1 19940228; PL 274547 A1 19890502; PT 88473 A 19881001; PT 88473 B 19921130; YU 171088 A 19900430; YU 46572 B 19931116

DOCDB simple family (application)

EP 88114157 A 19880831; AT 88114157 T 19880831; DE 3730367 A 19870910; DE 3888605 T 19880831; DK 493288 A 19880905; DK 495488 A 19880906; ES 88114157 T 19880831; FI 884071 A 19880902; GR 20000401261 T 20000531; IE 270788 A 19880907; PL 27454788 A 19880907; PT 8847388 A 19880909; YU 171088 A 19880908