Tepeln\u00e9 zpracov\u00e1n\u00ed: neupraven\u00e9, zpracov\u00e1n\u00ed v subtuh\u00e9m roztoku, zpracov\u00e1n\u00ed v tuh\u00e9m roztoku<\/em><\/p>\n <\/p>\n
Testov\u00e1n\u00ed tvrdosti<\/h3>\n
Oh\u00fdban\u00e1 \u010d\u00e1st teplosm\u011bnn\u00e9 trubky ve tvaru U bez tepeln\u00e9ho zpracov\u00e1n\u00ed a zpracov\u00e1n\u00ed v podtuh\u00e9m roztoku: s klesaj\u00edc\u00edm polom\u011brem ohybu se zvy\u0161uje hodnota tvrdosti. Hodnota tvrdosti teplosm\u011bnn\u00e9 trubky po rozpou\u0161t\u011bc\u00ed \u00faprav\u011b (ve srovn\u00e1n\u00ed s tvrdost\u00ed p\u0159ed oh\u00fdb\u00e1n\u00edm) se nem\u011bn\u00ed. To nazna\u010duje, \u017ee efekt mechanick\u00e9ho zpevn\u011bn\u00ed austenitick\u00e9 nerezov\u00e9 oceli je z\u0159ejm\u00fd a se zvy\u0161uj\u00edc\u00ed se deformac\u00ed se zvy\u0161uje trend zpev\u0148ov\u00e1n\u00ed.<\/p>\n
<\/p>\n
Mikroskopick\u00e1 kontrola<\/h3>\n
Pro \u010d\u00e1st ohybu ve tvaru U s polom\u011brem ohybu 40 mm: v mikrostruktu\u0159e je mnoho martenzitu a skluzov\u00fdch \u010dar bez tepeln\u00e9ho zpracov\u00e1n\u00ed a rovnoos\u00fd tvar austenitu v mikrostruktu\u0159e zcela zmizel (p\u0159\u00edli\u0161 mnoho martenzitu zp\u016fsob\u00ed, \u017ee ocel k\u0159ehk\u00fd). V\u011bt\u0161ina martenzitu v tk\u00e1ni o\u0161et\u0159en\u00e9 subsolidn\u00edm roztokem byla transformov\u00e1na, ale mal\u00e9 mno\u017estv\u00ed martenzitu st\u00e1le existuje.<\/p>\n
Po \u00faprav\u011b roztokem byla zrna austenitu rovnoos\u00e1 a nebyl nalezen \u017e\u00e1dn\u00fd martenzit. Skluzov\u00e9 p\u00e1sy a martenzit existovaly tak\u00e9 v nezah\u0159\u00e1t\u00e9 mikrostruktu\u0159e trubek ve tvaru U s polom\u011brem ohybu R 115, 190, 265 a 340 mm po ohybu, ale obsah postupn\u011b klesal s rostouc\u00edm polom\u011brem ohybu. Kdy\u017e je polom\u011br ohybu R trubky ve tvaru U v\u011bt\u0161\u00ed nebo roven 265 mm, vliv na mikrostrukturu p\u0159ed a po tepeln\u00e9m zpracov\u00e1n\u00ed nen\u00ed v\u00fdznamn\u00fd. Je-li polom\u011br ohybu R men\u0161\u00ed ne\u017e 265 mm, je v mikrostruktu\u0159e nezah\u0159\u00edvan\u00fdch trubek ve tvaru U martenzit a obsah martenzitu kles\u00e1 se zvy\u0161ov\u00e1n\u00edm teploty tepeln\u00e9ho zpracov\u00e1n\u00ed (zpracov\u00e1n\u00ed v subtuh\u00e9m roztoku a zpracov\u00e1n\u00ed v tuh\u00e9m roztoku).<\/p>\n
<\/p>\n
Zkou\u0161ka mezikrystalov\u00e9 koroze<\/h3>\n
Mikroskopick\u00fdm zkoum\u00e1n\u00edm bylo zji\u0161t\u011bno, \u017ee p\u0159\u00edtomnost martenzitu neovliv\u0148uje mezikrystalovou korozi. P\u0159esto\u017ee je v absolutizovan\u00e9 mikrostruktu\u0159e velk\u00e9 mno\u017estv\u00ed martenzitu, nen\u00ed zde tendence k mezikrystalov\u00e9 korozi spolu s distribuc\u00ed martenzitu. N\u011bkter\u00e9 hranice zrn se roz\u0161\u00ed\u0159ily p\u0159ed a po o\u0161et\u0159en\u00ed roztokem a roz\u0161\u00ed\u0159en\u00ed hranic zrn bylo nez\u00e1visl\u00e9 na distribuci martenzitu. Na z\u00e1klad\u011b mikroskopick\u00e9ho zkoum\u00e1n\u00ed po korozn\u00ed zkou\u0161ce byla provedena zkou\u0161ka ohybem pro trubky tvaru U v r\u016fzn\u00e9m stavu podle zku\u0161ebn\u00ed normy. Po ohnut\u00ed o 180\u00b0 nebyly v trubk\u00e1ch zji\u0161t\u011bny \u017e\u00e1dn\u00e9 mezikrystalov\u00e9 korozn\u00ed trhliny.<\/p>\n
<\/p>\n
Teplota zpracov\u00e1n\u00ed roztoku<\/h3>\n
\u00da\u010dinek \u00fapravy roztokem je ovlivn\u011bn n\u00edzkou teplotou roztoku a nelze z\u00edskat v\u00fdsledky mikrostruktury a tvrdosti. Pokud je teplota m\u00edrn\u011b vy\u0161\u0161\u00ed, mohou se uvnit\u0159 segmentu ve tvaru p\u00edsmene U objevit defekty, jako je konk\u00e1vn\u00ed nebo prasklina.<\/p>\n
<\/p>\n
Z experimentu je zn\u00e1mo, \u017ee p\u0159i martenzitick\u00e9 p\u0159em\u011bn\u011b nerezov\u00e9 oceli po zpracov\u00e1n\u00ed za studena je vliv korozn\u00ed odolnosti daleko v\u011bt\u0161\u00ed ne\u017e nap\u011bt\u00ed. Kdy\u017e je polom\u011br ohybu trubky ve tvaru U men\u0161\u00ed ne\u017e 115 mm, mikrostruktura trubky ve tvaru U p\u0159ed a po \u00faprav\u011b roztokem je v\u00fdrazn\u011b odli\u0161n\u00e1. U tohoto segmentu ohybu trubky ve tvaru p\u00edsmene U s mal\u00fdm polom\u011brem by m\u011blo b\u00fdt o\u0161et\u0159en\u00ed pevn\u00fdm roztokem provedeno po tv\u00e1\u0159en\u00ed za studena. Pokud neexistuje po\u017eadavek na vy\u0161\u0161\u00ed odolnost proti mezikrystalov\u00e9 korozi, doporu\u010duje se, aby ohybov\u00e1 \u010d\u00e1st ve tvaru U s polom\u011brem ohybu men\u0161\u00edm nebo rovn\u00fdm 265 mm byla o\u0161et\u0159ena roztokovou \u00fapravou (pozn\u00e1mka k odstran\u011bn\u00ed zbytkov\u00e9ho nap\u011bt\u00ed). U teplosm\u011bnn\u00fdch trubek ve tvaru U s velk\u00fdm polom\u011brem zak\u0159iven\u00ed nesm\u00ed b\u00fdt oh\u00fdban\u00e1 \u010d\u00e1st o\u0161et\u0159ena roztokem, s v\u00fdjimkou prost\u0159ed\u00ed citliv\u00fdch na korozi nam\u00e1h\u00e1n\u00edm. Vzhledem k tomu, \u017ee odpor kapaliny o mal\u00e9m pr\u016fm\u011bru potrub\u00ed je velk\u00fd, je nepohodln\u00e9 \u010distit a snadno blokovat strukturu a odpor kapaliny z nerezov\u00e9 oceli s velk\u00fdm pr\u016fm\u011brem nen\u00ed tak velk\u00fd jako mal\u00fd pr\u016fm\u011br potrub\u00ed, snadno se \u010dist\u00ed, v\u00edce se pou\u017e\u00edv\u00e1 pro visk\u00f3zn\u00ed nebo \u0161pinav\u00e1 tekutina.<\/p>\n
<\/p>\n
WLD Company m\u016f\u017ee poskytnout teplosm\u011bnn\u00e9 trubky z nerezov\u00e9 oceli 304\/316 od 10 mm do 114 mm, tlou\u0161\u0165ka 0,6 mm a\u017e 3,0 mm; D\u00e9lku lze upravit podle va\u0161ich skute\u010dn\u00fdch pracovn\u00edch podm\u00ednek. Pokud to pot\u0159ebujete, kontaktujte n\u00e1s je\u0161t\u011b dnes.<\/em><\/p>","protected":false},"excerpt":{"rendered":"Kdy\u017e mluv\u00edme o tepeln\u00e9m zpracov\u00e1n\u00ed austenitick\u00fdch trubek z nerezov\u00e9 oceli ve tvaru U, v\u011bt\u0161ina lid\u00ed si mysl\u00ed, \u017ee to nen\u00ed nutn\u00e9 kv\u016fli senzibilizaci a vysok\u00e9 teplot\u011b zpracov\u00e1n\u00ed roztoku, je snadn\u00e9 zp\u016fsobit deformaci trubky. Ve skute\u010dnosti je tepeln\u00e9 zpracov\u00e1n\u00ed austenitick\u00e9 nerezov\u00e9 oceli nevyhnuteln\u00e9, tepeln\u00e9 zpracov\u00e1n\u00ed nem\u016f\u017ee zm\u011bnit strukturu nerezov\u00e9 [\u2026]<\/p>","protected":false},"author":1,"featured_media":2212,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":["post-2211","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\/2211","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=2211"}],"version-history":[{"count":4,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts\/2211\/revisions"}],"predecessor-version":[{"id":2216,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts\/2211\/revisions\/2216"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/media\/2212"}],"wp:attachment":[{"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/media?parent=2211"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/categories?post=2211"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/tags?post=2211"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}