Co zp\u016fsobuje d\u016flkovou korozi?<\/h2>\n
Nej\u010dast\u011bji doch\u00e1z\u00ed k d\u016flkov\u00e9 korozi v d\u016fsledku depasivace mal\u00e9 oblasti. Tato mal\u00e1 oblast se st\u00e1v\u00e1 anodickou, zat\u00edmco okoln\u00ed oblast se st\u00e1v\u00e1 katodou. To vede k lok\u00e1ln\u00ed korozi.<\/p>\n
Co v\u0161ak zp\u016fsobuje depasivaci? Drobn\u00e9 vady, jako jsou praskliny, vrypy a \u0161kr\u00e1bance! Mal\u00e9 \u0161kr\u00e1bance na povrchu kovu se nemus\u00ed zd\u00e1t jako velk\u00e1 hrozba, ale tyto drobn\u00e9 od\u011brky mohou po\u0161kodit ochrann\u00fd povlak kovu a naru\u0161it jeho pasivitu. Mezi nej\u010dast\u011bj\u0161\u00ed p\u0159\u00ed\u010diny d\u016flkov\u00e9 koroze pat\u0159\u00ed:<\/p>\n
- \n
- Trhliny<\/li>\n
- \u0160kr\u00e1bance<\/li>\n
- Chipsy<\/li>\n
- Nerovnom\u011brn\u00e9 nap\u011bt\u00ed<\/li>\n
- Vadn\u00fd kovov\u00fd substr\u00e1t<\/li>\n
- P\u016fsoben\u00ed turbulentn\u00ed tekutiny<\/li>\n
- Nestejnom\u011brn\u00fd ochrann\u00fd povlak<\/li>\n
- Chemick\u00e9 \u00fatoky<\/li>\n<\/ul>\n
Pokud je tedy v\u00e1\u0161 kov jakkoli po\u0161kozen nebo vystaven rozbou\u0159en\u00e9 vod\u011b, sledujte, zda se na n\u011bm neobjevuj\u00ed d\u016flky. Dal\u0161\u00ed mo\u017enou p\u0159\u00ed\u010dinou vzniku d\u016flkov\u00e9 vady je rozd\u00edln\u00e9 provzdu\u0161\u0148ov\u00e1n\u00ed. Kdy\u017e je \u0161patn\u011b udr\u017eovan\u00fd kov vystaven p\u016fsoben\u00ed vody nebo prachov\u00fdch \u010d\u00e1stic, doch\u00e1z\u00ed k odkysli\u010den\u00ed mal\u00e9 oblasti. To zp\u016fsob\u00ed rozd\u00edl v provzdu\u0161n\u011bn\u00ed mezi n\u00ed a okol\u00edm. Dojde k reakci a na povrchu kovu se vytvo\u0159\u00ed rezav\u00e9 d\u016flky.<\/p>\n
Jak rozpoznat d\u016flkovou korozi<\/h2>\n
Mnoho lid\u00ed pova\u017euje d\u016flkovou korozi za jednu z nejnebezpe\u010dn\u011bj\u0161\u00edch forem koroze, proto\u017ee je obt\u00ed\u017en\u00e9 ji p\u0159edv\u00eddat, odhalit a p\u0159edch\u00e1zet j\u00ed. Mo\u017en\u00e1 si \u0159\u00edk\u00e1te: \"Po\u010dkat, kdy\u017e se na povrchu kovu vytv\u00e1\u0159ej\u00ed d\u016flky, nem\u011blo by b\u00fdt snadn\u00e9 ji odhalit?\". Nane\u0161t\u011bst\u00ed jsou d\u016flky, kter\u00e9 vytv\u00e1\u0159\u00ed, neuv\u011b\u0159iteln\u011b mal\u00e9. V\u011bt\u0161ina z nich je pro lidsk\u00e9 oko neviditeln\u00e1 (nebo t\u00e9m\u011b\u0159 neviditeln\u00e1). B\u011b\u017en\u011b jsou tak\u00e9 pokryty vrstvou koroze, co\u017e jejich odhalen\u00ed je\u0161t\u011b zt\u011b\u017euje.<\/p>\n
Zat\u00edmco rozpoznat d\u016flkovou korozi pouh\u00fdm okem je t\u00e9m\u011b\u0159 nemo\u017en\u00e9, existuj\u00ed\u00a0jsou<\/em>\u00a0spolehliv\u00e9 zp\u016fsoby testov\u00e1n\u00ed. Testov\u00e1n\u00ed m\u016f\u017ee zabr\u00e1nit vzniku d\u016flkov\u00e9 vady, proto doporu\u010dujeme n\u00e1chyln\u00e9 materi\u00e1ly \u010dasto testovat. Mezi b\u011b\u017en\u00e9 metody testov\u00e1n\u00ed d\u016flkov\u00e9 koroze pat\u0159\u00ed:<\/p>\n
Vizu\u00e1ln\u00ed prohl\u00eddka<\/h3>\n
Odborn\u00edk pomoc\u00ed mikroskopu spo\u010d\u00edt\u00e1 po\u010det jamek v dan\u00e9 oblasti. To mu pom\u016f\u017ee ur\u010dit jejich velikost a rozlo\u017een\u00ed i intenzitu.<\/p>\n
Sonick\u00e9 testov\u00e1n\u00ed<\/h3>\n
P\u0159i sonick\u00e9 zkou\u0161ce se ultrazvukov\u00e1 energie p\u0159en\u00e1\u0161\u00ed p\u0159es spojku na kov. Tyto ultrazvukov\u00e9 impulsy se odr\u00e1\u017eej\u00ed od kovu a p\u0159ev\u00e1d\u011bj\u00ed se na elektrick\u00e9 sign\u00e1ly. Tyto sign\u00e1ly zobraz\u00ed um\u00edst\u011bn\u00ed d\u016flk\u016f a jin\u00fdch nedokonalost\u00ed v kovu.<\/p>\n
Elektromagnetick\u00e9 testov\u00e1n\u00ed<\/h3>\n
Tato zku\u0161ebn\u00ed metoda se pou\u017e\u00edv\u00e1 k vyhled\u00e1v\u00e1n\u00ed nepravidelnost\u00ed na povrchu vodiv\u00fdch kov\u016f, jako je ocel a \u017eelezo.<\/p>\n
Elektrochemick\u00e9 testov\u00e1n\u00ed<\/h3>\n
Elektrochemick\u00e9 zkou\u0161ky jsou dal\u0161\u00edm zp\u016fsobem testov\u00e1n\u00ed rychlosti koroze kov\u016f. P\u0159i zkou\u0161ce se na pracovn\u00ed elektrodu kovu p\u0159iv\u00e1d\u00ed elektrick\u00fd proud, kter\u00fd vytv\u00e1\u0159\u00ed m\u011b\u0159iteln\u00e9 sign\u00e1ly.<\/p>\n
Zkou\u0161ka pono\u0159en\u00edm<\/h3>\n
Kus kovu se pono\u0159\u00ed do roztoku. Nech\u00e1 se n\u011bkolik dn\u00ed odst\u00e1t. Po vyjmut\u00ed se zm\u011b\u0159\u00ed rychlost koroze a d\u016flky se prozkoumaj\u00ed pod mikroskopem, aby se d\u00e1le ur\u010dil rozsah a intenzita.<\/p>\n
Jak\u00e9 materi\u00e1ly jsou nejv\u00edce ohro\u017eeny?<\/h2>\n
Materi\u00e1ly obsahuj\u00edc\u00ed bromidov\u00e9, chloridov\u00e9 nebo chlornanov\u00e9 ionty jsou nejn\u00e1chyln\u011bj\u0161\u00ed k d\u016flkov\u00e9 korozi. Zv\u00fd\u0161en\u00e9mu riziku jsou vystaveny tak\u00e9 materi\u00e1ly vystaven\u00e9 roztok\u016fm obsahuj\u00edc\u00edm fluoridy nebo jodity (jako je voda nebo sulfidy). N\u011bkter\u00e9 kovy n\u00e1chyln\u00e9 k d\u016flkov\u00e9 korozi jsou:<\/p>\n
- \n
- Chrom<\/li>\n
- Nerezov\u00e1 ocel<\/li>\n
- Rtu\u0165<\/li>\n
- Kobalt<\/li>\n
- Hlin\u00edk<\/li>\n
- M\u011b\u010f<\/li>\n<\/ul>\n
Prevence \u0161t\u011brbinov\u00e9 koroze<\/h2>\n
Krom\u011b toho, \u017ee v\u00edte, jak identifikovat a odstranit d\u016flkovou korozi, byste pravd\u011bpodobn\u011b m\u011bli v\u011bd\u011bt, jak d\u016flkov\u00e9 korozi p\u0159edch\u00e1zet. Existuje n\u011bkolik zp\u016fsob\u016f, jak minimalizovat riziko vzniku d\u016flkov\u00e9 koroze.<\/p>\n
Jedn\u00edm z prvn\u00edch preventivn\u00edch opat\u0159en\u00ed je pou\u017eit\u00ed materi\u00e1l\u016f odoln\u00fdch proti korozi. Slitiny obsahuj\u00edc\u00ed titan, dus\u00edk, chrom a molybden dob\u0159e odol\u00e1vaj\u00ed d\u016flkov\u00e9 korozi. Dal\u0161\u00ed \u00fa\u010dinnou metodou prevence je katodick\u00e1 ochrana,<\/a> kter\u00fd zabra\u0148uje korozi t\u00edm, \u017ee m\u011bn\u00ed kovov\u00fd povrch v elektrochemick\u00fd \u010dl\u00e1nek. V ide\u00e1ln\u00edm p\u0159\u00edpad\u011b byste m\u011bli materi\u00e1l pokr\u00fdt reaktivn\u011bj\u0161\u00edm kovem. Tento korozivn\u011b aktivn\u00ed kov bude fungovat jako anoda a bude korodovat m\u00edsto p\u016fvodn\u00edho kovu, \u010d\u00edm\u017e zabr\u00e1n\u00ed vzniku d\u016flkov\u00e9 koroze.<\/p>\n
Dal\u0161\u00edm z nej\u00fa\u010dinn\u011bj\u0161\u00edch zp\u016fsob\u016f, jak zabr\u00e1nit d\u016flkov\u00e9 korozi, je co nejl\u00e9pe kontrolovat faktory prost\u0159ed\u00ed (vlhkost, teplota, chloridy, pH kyselin a soli). Mezi dal\u0161\u00ed metody prevence d\u016flkov\u00e9 koroze pat\u0159\u00ed pou\u017e\u00edv\u00e1n\u00ed a udr\u017eov\u00e1n\u00ed ochrann\u00e9ho n\u00e1t\u011bru a kontrola vystaven\u00ed kapalin\u00e1m a prachu.<\/p>\n
Lze odstranit d\u016flkovou korozi?<\/h2>\n
Mo\u017en\u00e1 v\u00e1s pot\u011b\u0161\u00ed, \u017ee na rozd\u00edl od v\u011bt\u0161iny forem koroze je bodov\u00e1 koroze odstraniteln\u00e1. Za p\u0159edpokladu, \u017ee je kov struktur\u00e1ln\u011b st\u00e1le zdrav\u00fd, m\u016f\u017eete korozi odstranit \u0161etrnou kyselinou. Pokud chcete odstranit skute\u010dnou d\u016flkovou korozi, budete muset kov obrousit, o\u0161kr\u00e1bat nebo op\u00edskovat. D\u016fln\u00ed vrypy m\u016f\u017eete odstranit tak\u00e9 mechanicky.<\/p>\n
Po odstran\u011bn\u00ed koroze a d\u016flkov\u00e9 koroze je t\u0159eba kov opat\u0159it z\u00e1kladn\u00edm n\u00e1t\u011brem n\u011bkterou z n\u00e1sleduj\u00edc\u00edch metod:<\/p>\n
- \n
- Z\u00e1kladn\u00ed n\u00e1t\u011br fosfore\u010dnanem zinku<\/li>\n
- Metalizace zinkov\u00fdm n\u00e1st\u0159ikem<\/li>\n
- Chemick\u00fd n\u00e1t\u011br<\/li>\n
- Nam\u00e1\u010den\u00ed za tepla<\/li>\n<\/ul>\n
Hled\u00e1te zp\u016fsoby, jak zabr\u00e1nit d\u016flkov\u00e9 korozi? Odborn\u00edci ze spole\u010dnosti Dreiym Engineering v\u00e1m mohou pomoci! Nab\u00edz\u00edme\u00a0testov\u00e1n\u00ed korozn\u00ed agresivity p\u016fdy<\/strong><\/a>\u00a0k m\u011b\u0159en\u00ed korozn\u00ed agresivity p\u016fdy, ve kter\u00e9 jsou kovov\u00e9 sou\u010d\u00e1sti zakop\u00e1ny. Rovn\u011b\u017e navrhov\u00e1n\u00ed a instalace katodick\u00e9 ochrany<\/a> syst\u00e9my, aby se d\u00e1le sn\u00ed\u017eilo riziko vzniku d\u016flk\u016f. Kontaktujte n\u00e1s je\u0161t\u011b dnes a z\u00edskejte v\u00edce informac\u00ed o na\u0161ich slu\u017eb\u00e1ch v oblasti prevence koroze nebo si domluvte konzultaci.<\/p>\n
![\"Jak](\"https:\/\/vm6fr4whzn6.c.updraftclone.com\/wp-content\/uploads\/2022\/02\/Remove-Pitting-Corrosion.jpg\")
","protected":false},"excerpt":{"rendered":"Corrosion is the enemy of metals of all kinds. This damaging process causes metal materials to gradually rust and degrade; and often, it attacks sneakily, undetectable until the damage is already done. What makes corrosion even harder to detect and prevent is that it comes in many forms. One of these is pitting corrosion, regarded […]<\/p>\n","protected":false},"author":8,"featured_media":3453,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"_mbp_gutenberg_autopost":false,"_pgmb_is_evergreen":true,"_pgmb_ap_template_id":0,"iawp_total_views":602,"footnotes":""},"categories":[5],"tags":[],"class_list":["post-3053","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-corrosion-and-cathodic-protection"],"acf":[],"aioseo_notices":[],"aioseo_head":"\n\t\t\n\t\n\t\n\t\n\t\n\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t\n\t\t