{"id":2179,"date":"2021-07-19T06:18:56","date_gmt":"2021-07-19T06:18:56","guid":{"rendered":"https:\/\/wldstainless.com\/?p=2179"},"modified":"2021-07-19T08:32:55","modified_gmt":"2021-07-19T08:32:55","slug":"the-advantages-of-904l-stainless-steel","status":"publish","type":"post","link":"https:\/\/wldstainless.com\/cs\/the-advantages-of-904l-stainless-steel\/","title":{"rendered":"V\u00fdhody nerezov\u00e9 oceli 904L"},"content":{"rendered":"<p>Super austenitick\u00e1 nerezov\u00e1 ocel 904L (<a href=\"https:\/\/wldstainless.com\/materials\/austenitic-stainless-steel\/904l-stainless-steel\/\">UNS N08904<\/a>, EN1.4539) je vysoce legovan\u00e1 austenitick\u00e1 nerezov\u00e1 ocel s n\u00edzk\u00fdm obsahem uhl\u00edku, speci\u00e1ln\u011b navr\u017een\u00e1 pro drsn\u00e9 korozn\u00ed podm\u00ednky. M\u00e1 vysok\u00fd obsah chr\u00f3mu a niklu, d\u00edky p\u0159\u00eddavku m\u011bdi m\u00e1 silnou odolnost proti kyselin\u00e1m, zejm\u00e9na z\u0159ed\u011bn\u00e9 kyselin\u011b s\u00edrov\u00e9, zvl\u00e1\u0161t\u011b vysokou odolnost proti korozi chloridov\u00e9 mezery a prask\u00e1n\u00ed koroz\u00ed pod nap\u011bt\u00edm, nen\u00ed snadn\u00e9 objevit erozn\u00ed skvrny a praskliny, odolnost proti d\u016flkov\u00e9 korozi je nepatrn\u00e1 lep\u0161\u00ed ne\u017e jin\u00e1 ocel. M\u00e1 dobrou obrobitelnost a sva\u0159itelnost, v mnoha pr\u016fmyslov\u00fdch oblastech m\u00e1 \u0161irokou \u0161k\u00e1lu aplikac\u00ed: petrochemick\u00e9 n\u00e1doby a potrub\u00ed, jako jsou reaktory atd.; Jednotka ods\u00ed\u0159en\u00ed spalin elektr\u00e1rny; \u00dapravna mo\u0159sk\u00e9 vody, tepeln\u00fd v\u00fdm\u011bn\u00edk mo\u0159sk\u00e9 vody; Za\u0159\u00edzen\u00ed pro pap\u00edrensk\u00fd pr\u016fmysl, farmaceutick\u00fd pr\u016fmysl, potravin\u00e1\u0159sk\u00fd pr\u016fmysl a dal\u0161\u00ed obory.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Metalografick\u00e1 struktura<\/strong><\/p>\n<p>904L je zcela austenitick\u00fd. Ve srovn\u00e1n\u00ed s austenitick\u00fdmi nerezov\u00fdmi oceli s vysok\u00fdm obsahem molybdenu je 904L necitliv\u00fd na sr\u00e1\u017een\u00ed feritu a f\u00e1ze \u03b1.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Sva\u0159ovac\u00ed v\u00fdkon<\/strong><\/p>\n<p>Stejn\u011b jako u b\u011b\u017en\u00e9 nerezov\u00e9 oceli lze 904 L sva\u0159ovat r\u016fzn\u00fdmi zp\u016fsoby. Nej\u010dast\u011bji pou\u017e\u00edvan\u00e9 metody sva\u0159ov\u00e1n\u00ed jsou ru\u010dn\u00ed obloukov\u00e9 sva\u0159ov\u00e1n\u00ed nebo sva\u0159ov\u00e1n\u00ed v ochrann\u00e9 atmosf\u00e9\u0159e inertn\u00edho plynu. Elektroda nebo dr\u00e1tov\u00fd kov je zalo\u017een na slo\u017een\u00ed z\u00e1kladn\u00edho kovu a m\u00e1 vy\u0161\u0161\u00ed \u010distotu. Obsah molybdenu je vy\u0161\u0161\u00ed ne\u017e u obecn\u00e9ho kovu. P\u0159ed sva\u0159ov\u00e1n\u00edm se obecn\u011b nevy\u017eaduje p\u0159edeh\u0159ev, s v\u00fdjimkou chladn\u00e9ho venkovn\u00edho prost\u0159ed\u00ed, aby se zabr\u00e1nilo kondenzaci vodn\u00ed p\u00e1ry, lze spojovou \u010d\u00e1st nebo p\u0159ilehlou oblast rovnom\u011brn\u011b zah\u0159\u00e1t. Pamatujte, \u017ee m\u00edstn\u00ed teplota by nem\u011bla p\u0159ekro\u010dit 100 \u2103, aby nedoch\u00e1zelo k hromad\u011bn\u00ed uhl\u00edku a mezikrystalov\u00e9 korozi. Pro sva\u0159ov\u00e1n\u00ed by m\u011bla b\u00fdt pou\u017eita mal\u00e1 energie veden\u00ed, kontinuita a vysok\u00e1 rychlost sva\u0159ov\u00e1n\u00ed. Obecn\u011b se po sva\u0159ov\u00e1n\u00ed nevy\u017eaduje tepeln\u00e9 zpracov\u00e1n\u00ed. Pokud je pot\u0159eba tepeln\u00e9 zpracov\u00e1n\u00ed, mus\u00ed se zah\u0159\u00e1t na 1100 ~ 1150 \u2103 a pot\u00e9 rychle ochlazovat. Vhodn\u00e9 sva\u0159ovac\u00ed materi\u00e1ly: elektroda (E385-16\/17), sva\u0159ovac\u00ed dr\u00e1t (ER385).<\/p>\n<p>&nbsp;<\/p>\n<p><strong>V\u00fdkon obr\u00e1b\u011bn\u00ed<\/strong><\/p>\n<p>Vlastnosti obr\u00e1b\u011bn\u00ed <a href=\"https:\/\/wldstainless.com\/materials\/austenitic-stainless-steel\/904l-stainless-steel\/\">904 l<\/a> jsou podobn\u00e9 jako u jin\u00fdch austenitick\u00fdch korozivzdorn\u00fdch ocel\u00ed a b\u011bhem obr\u00e1b\u011bn\u00ed existuje tendence k lepivosti fr\u00e9zy a mechanick\u00e9mu zpevn\u011bn\u00ed. Mus\u00ed b\u00fdt pou\u017eity kladn\u00e9 p\u0159edn\u00ed \u00fahlov\u00e9 \u0159ezn\u00e9 n\u00e1stroje z tvrdokovu s vulkanizac\u00ed a chlorovan\u00fdm olejem jako \u0159ezn\u00fdm chladivem. P\u0159edpokladem by m\u011blo b\u00fdt za\u0159\u00edzen\u00ed a proces ke sn\u00ed\u017een\u00ed mechanick\u00e9ho zpevn\u011bn\u00ed. V procesu \u0159ez\u00e1n\u00ed je t\u0159eba se vyvarovat pomal\u00e9 \u0159ezn\u00e9 rychlosti a posuvu.<\/p>\n<p>&nbsp;<\/p>\n<p><strong>Odolnost proti korozi nerezov\u00e9 oceli 904L<\/strong><\/p>\n<p>904L m\u00e1 dobrou schopnost p\u0159em\u011bny aktivace-pasivace, m\u00e1 vynikaj\u00edc\u00ed odolnost proti korozi, odolnost proti d\u016flkov\u00e9 korozi, dobrou odolnost proti korozi trhlin a odolnost proti korozi nam\u00e1h\u00e1n\u00edm v neoxida\u010dn\u00ed kyselin\u011b, jako je kyselina s\u00edrov\u00e1, kyselina octov\u00e1, kyselina mraven\u010d\u00ed, kyselina fosfore\u010dn\u00e1, m\u00e1 dobrou odolnost proti korozi, v neutr\u00e1ln\u00edm m\u00e9diu obsahuj\u00edc\u00edm chloridov\u00e9 ionty. Je vhodn\u00fd pro v\u0161echny koncentrace kyseliny s\u00edrov\u00e9 pod 70 \u2103 a m\u00e1 dobrou odolnost proti korozi v\u016f\u010di kyselin\u011b octov\u00e9 a sm\u011bsi kyseliny mraven\u010d\u00ed a kyseliny octov\u00e9 p\u0159i jak\u00e9koli koncentraci a jak\u00e9koli teplot\u011b za norm\u00e1ln\u00edho tlaku.<\/p>\n<p>D\u00edky n\u00edzk\u00e9mu obsahu uhl\u00edku (max. 0,020%) 904L nedoch\u00e1z\u00ed za norm\u00e1ln\u00edch podm\u00ednek tepeln\u00e9ho zpracov\u00e1n\u00ed a sva\u0159ov\u00e1n\u00ed k \u017e\u00e1dn\u00e9mu vysr\u00e1\u017een\u00ed karbidu. To eliminuje mo\u017enost mezikrystalov\u00e9 koroze, kter\u00e1 se b\u011b\u017en\u011b vyskytuje po tepeln\u00e9m zpracov\u00e1n\u00ed a sva\u0159ov\u00e1n\u00ed. Vysok\u00fd obsah Cr-Ni-Mo a p\u0159\u00eddavek m\u011bdi \u010din\u00ed 904L pasivovan\u00fdm i v reduk\u010dn\u00edch prost\u0159ed\u00edch, jako je kyselina s\u00edrov\u00e1 a kyselina mraven\u010d\u00ed. D\u00edky vysok\u00e9mu obsahu niklu m\u00e1 v aktivn\u00edm stavu n\u00edzkou rychlost koroze. V koncentra\u010dn\u00edm rozsahu 0~98% \u010dist\u00e9 kyseliny s\u00edrov\u00e9 lze 904L pou\u017e\u00edt p\u0159i teplot\u011b do 40\u2103. V koncentra\u010dn\u00edm rozsahu 0~85% \u010dist\u00e9 kyseliny fosfore\u010dn\u00e9 m\u00e1 st\u00e1le dobrou odolnost proti korozi.<\/p>\n<p><a href=\"https:\/\/wldstainless.com\/materials\/austenitic-stainless-steel\/904l-stainless-steel\/\">904L SS<\/a> je lep\u0161\u00ed ne\u017e b\u011b\u017en\u00e1 nerezov\u00e1 ocel v odolnosti v\u016f\u010di v\u0161em fosf\u00e1t\u016fm. Ve vysoce oxiduj\u00edc\u00ed kyselin\u011b dusi\u010dn\u00e9 m\u00e1 904L \u0161patnou odolnost proti korozi ve srovn\u00e1n\u00ed s legovanou ocel\u00ed bez molybdenu. V kyselin\u011b chlorovod\u00edkov\u00e9 je pou\u017eit\u00ed 904L omezeno na ni\u017e\u0161\u00ed koncentraci 1-2%, kde je jej\u00ed odolnost proti korozi lep\u0161\u00ed ne\u017e u b\u011b\u017en\u00e9 nerezov\u00e9 oceli. Ocel 904L m\u00e1 silnou odolnost proti \u0161t\u011brbinov\u00e9 korozi v roztoc\u00edch chlorid\u016f, koncentrovan\u00fdch roztoc\u00edch hydroxid\u016f a v prost\u0159ed\u00edch bohat\u00fdch na sirovod\u00edk, d\u00edky vysok\u00e9mu obsahu niklu, kter\u00fd sni\u017euje rychlost koroze v d\u016flc\u00edch a \u0161t\u011brbin\u00e1ch. B\u011b\u017en\u00e9 austenitick\u00e9 nerezov\u00e9 oceli mohou b\u00fdt citliv\u00e9 na korozi pod nap\u011bt\u00edm p\u0159i teplot\u00e1ch nad 60 \u00b0C v prost\u0159ed\u00ed bohat\u00e9m na chloridy. Tuto citlivost lze sn\u00ed\u017eit zv\u00fd\u0161en\u00edm obsahu niklu v nerezov\u00e9 oceli.<\/p>","protected":false},"excerpt":{"rendered":"<p>Super austenitick\u00e1 nerezov\u00e1 ocel 904L (UNS N08904, EN1.4539) je vysoce legovan\u00e1 austenitick\u00e1 nerezov\u00e1 ocel s n\u00edzk\u00fdm obsahem uhl\u00edku, speci\u00e1ln\u011b navr\u017een\u00e1 pro drsn\u00e9 korozn\u00ed podm\u00ednky. M\u00e1 vysok\u00fd obsah chr\u00f3mu a niklu, d\u00edky p\u0159\u00eddavku m\u011bdi m\u00e1 silnou odolnost v\u016f\u010di kyselin\u00e1m, zejm\u00e9na z\u0159ed\u011bn\u00e9 kyselin\u011b s\u00edrov\u00e9, obzvl\u00e1\u0161t\u011b vysokou odolnost v\u016f\u010di korozi chloridov\u00e9 mezery a [\u2026]<\/p>","protected":false},"author":1,"featured_media":2180,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":["post-2179","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-news"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts\/2179","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/comments?post=2179"}],"version-history":[{"count":1,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts\/2179\/revisions"}],"predecessor-version":[{"id":2181,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts\/2179\/revisions\/2181"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/media\/2180"}],"wp:attachment":[{"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/media?parent=2179"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/categories?post=2179"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/tags?post=2179"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}