{"id":353,"date":"2025-10-06T06:13:56","date_gmt":"2025-10-06T06:13:56","guid":{"rendered":"https:\/\/pwhtsolutions.net\/?p=353"},"modified":"2025-10-06T06:13:56","modified_gmt":"2025-10-06T06:13:56","slug":"pozadavky-na-tepelne-zpracovani-po-svarovani-podle-oddilu-viii-normy-asme","status":"publish","type":"post","link":"http:\/\/pwhtsolutions.net\/cs\/post-weld-heat-treatment-requirement-as-per-asme-section-viii\/","title":{"rendered":"Po\u017eadavky na tepeln\u00e9 zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed podle odd\u00edlu VIII ASME"},"content":{"rendered":"

Tepeln\u00e9 zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed (PWHT) sni\u017euje nap\u011bt\u00ed, zlep\u0161uje ta\u017enost a pom\u00e1h\u00e1 p\u0159edch\u00e1zet prask\u00e1n\u00ed n\u00e1dob z uhl\u00edkov\u00e9 oceli siln\u011bj\u0161\u00edch ne\u017e 38 mm a slitin n\u00e1chyln\u00fdch k prask\u00e1n\u00ed, jak je stanoveno v odd\u00edlu VIII ASME. Krom\u011b toho lze tento proces vyu\u017e\u00edt tak\u00e9 u sou\u010d\u00e1st\u00ed trupu letadel, lopatek turb\u00edn a sou\u010d\u00e1st\u00ed podvozk\u016f.<\/p>\n

M\u00edstn\u00ed PWHT lze pou\u017e\u00edt ke zm\u00edrn\u011bn\u00ed zbytkov\u00e9ho nap\u011bt\u00ed zp\u016fsoben\u00e9ho vysok\u00fdmi teplotn\u00edmi gradienty mezi svarov\u00fdmi kovy a z\u00e1kladn\u00edmi kovy a tento \u010dl\u00e1nek se bude zab\u00fdvat v\u0161emi po\u017eadavky a v\u00fdjimkami podle odd\u00edlu VIII, divize 1 ASME.<\/p>\n

Kvalifikace<\/h2>\n

PWHT je nezbytn\u00e1 v pr\u016fmyslov\u00fdch odv\u011btv\u00edch s vysok\u00fdmi s\u00e1zkami, jako jsou ropovody a plynovody, tlakov\u00e9 n\u00e1doby a plo\u0161iny na mo\u0159i; je povinn\u00e1 pro n\u00e1doby z uhl\u00edkov\u00e9 oceli siln\u011bj\u0161\u00ed ne\u017e 38 mm; je nezbytn\u00e1 v leteck\u00fdch konstrukc\u00edch v\u010detn\u011b podvozk\u016f a sou\u010d\u00e1st\u00ed trupu. Nedodr\u017een\u00ed specifikac\u00ed ASME t\u00fdkaj\u00edc\u00edch se PWHT m\u016f\u017ee m\u00edt za n\u00e1sledek odm\u00edtnut\u00ed svar\u016f, n\u00e1kladn\u00e9 p\u0159epracov\u00e1n\u00ed a potenci\u00e1ln\u00ed ohro\u017een\u00ed bezpe\u010dnosti; z tohoto d\u016fvodu je povinn\u00e9, aby sv\u00e1\u0159e\u010di p\u0159ed zah\u00e1jen\u00edm prac\u00ed na PWHT m\u011bli kvalifikaci jak pro sva\u0159ovac\u00ed postupy, tak pro tepeln\u00e9 zpracov\u00e1n\u00ed.<\/p>\n

P\u0159edeh\u0159ev a n\u00e1sledn\u00e9 tepeln\u00e9 zpracov\u00e1n\u00ed svar\u016f (PWHT) maj\u00ed zabr\u00e1nit vzniku trhlin, sn\u00ed\u017eit nap\u011bt\u00ed a zlep\u0161it vlastnosti. Proces PWHT zalo\u017een\u00fd na peci o\u0161et\u0159uje cel\u00e9 d\u00edly v peci; lok\u00e1ln\u00ed odporov\u00e9 oh\u0159\u00edva\u010de nebo podlo\u017eky o\u0161et\u0159uj\u00ed specifick\u00e9 z\u00f3ny svaru, nap\u0159\u00edklad potrub\u00ed.<\/p>\n

V\u00fdjimky<\/h2>\n

Odd\u00edl VIII ASME poskytuje komplexn\u00ed pokyny pro navrhov\u00e1n\u00ed, konstrukci, kontrolu, zkou\u0161en\u00ed a provoz tlakov\u00fdch n\u00e1dob. Slou\u017e\u00ed jako pr\u016fmyslov\u00fd standard pro zaji\u0161t\u011bn\u00ed bezpe\u010dn\u00fdch a spolehliv\u00fdch energetick\u00fdch kotl\u016f a dal\u0161\u00edch pr\u016fmyslov\u00fdch aplikac\u00ed.<\/p>\n

Tepeln\u00e9 zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed je ned\u00edlnou sou\u010d\u00e1st\u00ed sva\u0159ov\u00e1n\u00ed, kter\u00e9 pom\u00e1h\u00e1 sni\u017eovat zbytkov\u00e1 nap\u011bt\u00ed a zvy\u0161ovat hou\u017eevnatost svarov\u00fdch spoj\u016f. Obvykle zahrnuje zah\u0159\u00e1t\u00ed materi\u00e1l\u016f na teplotu ni\u017e\u0161\u00ed, ne\u017e je jejich ni\u017e\u0161\u00ed kritick\u00e1 teplota p\u0159etvo\u0159en\u00ed, po ur\u010ditou dobu a n\u00e1sledn\u00e9 udr\u017eov\u00e1n\u00ed t\u00e9to teploty po del\u0161\u00ed dobu.<\/p>\n

A\u010dkoli se tento postup m\u016f\u017ee zd\u00e1t n\u00e1ro\u010dn\u00fd, odd\u00edl VIII ASME poskytuje n\u011bkolik v\u00fdjimek, kter\u00e9 tento \u00fakol zjednodu\u0161uj\u00ed a \u010din\u00ed jej bezpe\u010dn\u011bj\u0161\u00edm. Pokud MDMT va\u0161eho materi\u00e1lu nedosahuje hodnoty uveden\u00e9 na obr. UCS 66, lze od r\u00e1zov\u00e9 zkou\u0161ky upustit, instalace pojistn\u00e9ho ventilu v\u0161ak z\u016fst\u00e1v\u00e1 povinn\u00e1. Chcete-li se ujistit, \u017ee v\u0161echny v\u00fdjimky funguj\u00ed tak, jak maj\u00ed, ne\u017e je sami vyzkou\u0161\u00edte; nejprve se pora\u010fte s certifikovan\u00fdm odborn\u00edkem, aby v\u00e1m mohl vysv\u011btlit, pro\u010d existuj\u00ed po\u017eadavky p\u0159edpis\u016f, a zaru\u010dit, \u017ee v\u00e1\u0161 projekt spl\u0148uje v\u0161echny bezpe\u010dnostn\u00ed normy.<\/p>\n

Podrobn\u00e9 po\u017eadavky<\/h2>\n

Tepeln\u00e9 zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed (PWHT) je \u0159\u00edzen\u00fd proces, p\u0159i kter\u00e9m se svarov\u00fd kov zah\u0159eje na teplotu ni\u017e\u0161\u00ed, ne\u017e je doln\u00ed mez kritick\u00e9ho p\u0159etvo\u0159en\u00ed, a udr\u017euje se v t\u00e9to teplot\u011b po p\u0159\u00edslu\u0161nou dobu po sva\u0159ov\u00e1n\u00ed. PWHT je vy\u017eadov\u00e1na p\u0159edpisy, jako je ASME Section VIII, aby se zabr\u00e1nilo selh\u00e1n\u00ed konstrukce v d\u016fsledku poruch vyvolan\u00fdch nap\u011bt\u00edm, a z\u00e1rove\u0148 se \u010dasto pou\u017e\u00edv\u00e1 v pr\u016fmyslov\u00fdch odv\u011btv\u00edch, jako je bezpe\u010dnost ropovod\u016f a plynovod\u016f, komponenty pro leteck\u00fd pr\u016fmysl (podvozky a trupy letadel), projekty mostn\u00edch konstrukc\u00ed, jako jsou kostry mrakodrap\u016f, a tak\u00e9 velk\u00e9 projekty konstruk\u010dn\u00edch staveb s pou\u017eit\u00edm metod, jako je odporov\u00fd oh\u0159ev v peci (es) nebo induk\u010dn\u00ed oh\u0159ev lokalizovan\u00fdch z\u00f3n svaru.<\/p>\n

Tepeln\u00e9 zpracov\u00e1n\u00ed<\/h2>\n

Tepeln\u00e9 zpracov\u00e1n\u00ed je proces pou\u017e\u00edvan\u00fd v metalurgick\u00e9m pr\u016fmyslu ke zm\u011bn\u011b fyzik\u00e1ln\u00edch vlastnost\u00ed kovu. \u017d\u00edh\u00e1n\u00ed, kalen\u00ed, sr\u00e1\u017ekov\u00e9 zpev\u0148ov\u00e1n\u00ed, popou\u0161t\u011bn\u00ed, nauhli\u010dov\u00e1n\u00ed a normalizace pat\u0159\u00ed k mnoha \u00fa\u010del\u016fm tepeln\u00e9ho zpracov\u00e1n\u00ed kovov\u00fdch d\u00edl\u016f.<\/p>\n

Tepeln\u00e9 zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed (PWHT) zahrnuje zah\u0159\u00e1t\u00ed obou svarov\u00fdch kov\u016f na teplotu ni\u017e\u0161\u00ed, ne\u017e je jejich kritick\u00e1 teplota p\u0159em\u011bny, po stanovenou dobu. Tento proces sni\u017euje zbytkov\u00e1 nap\u011bt\u00ed a mikrostrukturn\u00ed zm\u011bny zp\u016fsoben\u00e9 sva\u0159ov\u00e1n\u00edm a umo\u017e\u0148uje materi\u00e1l\u016fm z\u00edskat po sva\u0159ov\u00e1n\u00ed zp\u011bt svou pevnost; PWHT m\u016f\u017ee b\u00fdt povinn\u00e1 v z\u00e1vislosti na p\u0159edpisech, pokud jsou spln\u011bna ur\u010dit\u00e1 krit\u00e9ria.<\/p>\n

Cykly oh\u0159evu je t\u0159eba pe\u010dliv\u011b \u0159\u00eddit, proto\u017ee p\u0159\u00edli\u0161 rychl\u00fd n\u00e1r\u016fst teploty m\u016f\u017ee v\u00e9st k deformaci, zat\u00edmco nestejnom\u011brn\u00e9 rozlo\u017een\u00ed teploty m\u016f\u017ee v\u00e9st k prask\u00e1n\u00ed. Aplika\u010dn\u00ed p\u0159edpisy proto obvykle stanov\u00ed, \u017ee oblasti svaru, kter\u00e9 je t\u0159eba o\u0161et\u0159it, mus\u00ed b\u00fdt od neo\u0161et\u0159en\u00fdch \u010d\u00e1st\u00ed odd\u011bleny p\u0159im\u011b\u0159en\u011b malou mezerou. Metody PWHT zahrnuj\u00ed oh\u0159ev cel\u00e9 n\u00e1doby v peci a tak\u00e9 lok\u00e1ln\u00ed odporov\u00e9 o\u0161et\u0159en\u00ed pomoc\u00ed oh\u0159\u00edvac\u00edch podlo\u017eek nebo dek v ur\u010dit\u00fdch z\u00f3n\u00e1ch.<\/p>","protected":false},"excerpt":{"rendered":"

Tepeln\u00e9 zpracov\u00e1n\u00ed po sva\u0159ov\u00e1n\u00ed (PWHT) sni\u017euje nap\u011bt\u00ed, zlep\u0161uje ta\u017enost a pom\u00e1h\u00e1 p\u0159edch\u00e1zet prask\u00e1n\u00ed n\u00e1dob z uhl\u00edkov\u00e9 oceli siln\u011bj\u0161\u00edch ne\u017e 38 mm a slitin n\u00e1chyln\u00fdch k prask\u00e1n\u00ed, jak je stanoveno v odd\u00edlu VIII ASME. Krom\u011b toho lze tento proces vyu\u017e\u00edt tak\u00e9 u sou\u010d\u00e1st\u00ed trupu letadel, lopatek turb\u00edn a sou\u010d\u00e1st\u00ed podvozk\u016f. Lok\u00e1ln\u00ed PWHT lze pou\u017e\u00edt ... <\/p>\n

P\u0159e\u010dt\u011bte si v\u00edce “Post Weld Heat Treatment Requirement As Per ASME Section VIII”<\/span><\/a><\/p>","protected":false},"author":1,"featured_media":0,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[3],"tags":[],"class_list":["post-353","post","type-post","status-publish","format-standard","hentry","category-pwht-knowledge"],"aioseo_notices":[],"_links":{"self":[{"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/posts\/353","targetHints":{"allow":["GET"]}}],"collection":[{"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/comments?post=353"}],"version-history":[{"count":1,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/posts\/353\/revisions"}],"predecessor-version":[{"id":354,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/posts\/353\/revisions\/354"}],"wp:attachment":[{"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/media?parent=353"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/categories?post=353"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/pwhtsolutions.net\/cs\/wp-json\/wp\/v2\/tags?post=353"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}