{"id":2144,"date":"2021-05-13T13:40:57","date_gmt":"2021-05-13T13:40:57","guid":{"rendered":"https:\/\/wldstainless.com\/?p=2144"},"modified":"2021-05-13T13:50:56","modified_gmt":"2021-05-13T13:50:56","slug":"dual-grade-stainless-steel-304-304l-316-316l","status":"publish","type":"post","link":"https:\/\/wldstainless.com\/cs\/dual-grade-stainless-steel-304-304l-316-316l\/","title":{"rendered":"Dvojit\u00e1 nerezov\u00e1 ocel 304\/304L, 316\/316L"},"content":{"rendered":"<p>Austenitick\u00e9 nerezov\u00e9 oceli jsou nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00ed nerezov\u00e9 oceli, kter\u00e9 p\u0159edstavuj\u00ed asi 751 TP3T celkov\u00e9 spot\u0159eby nerezov\u00e9 oceli. Rychl\u00fd rozvoj chemick\u00e9ho pr\u016fmyslu a petrochemick\u00e9ho pr\u016fmyslu klade vy\u0161\u0161\u00ed po\u017eadavky na korozn\u00ed odolnost a pevnost nerezov\u00e9 oceli. Nap\u0159\u00edklad nerezov\u00e1 ocel dvoj\u00ed jakosti 304\/304L znamen\u00e1, \u017ee m\u00e1 ni\u017e\u0161\u00ed obsah uhl\u00edku, to je m\u00e9n\u011b ne\u017e 0,03%, co\u017e odpov\u00edd\u00e1 jakosti 304L, zat\u00edmco jej\u00ed mez kluzu a pevnosti v tahu jsou vy\u0161\u0161\u00ed ne\u017e spodn\u00ed limit nerezov\u00e9 oceli 304, nerezov\u00e1 ocel m\u016f\u017ee b\u00fdt definov\u00e1n jako <a href=\"https:\/\/wldstainless.com\/materials\/austenitic-stainless-steel\/304-304l-stainless-steel\/\">304\/304L<\/a> nerezov\u00e1 ocel dvoj\u00ed jakosti, to znamen\u00e1, \u017ee jej\u00ed chemick\u00e9 slo\u017een\u00ed odpov\u00edd\u00e1 slo\u017een\u00ed 304L a mechanick\u00e9 vlastnosti spl\u0148uj\u00ed po\u017eadavky nerezov\u00e9 oceli 304. Podobn\u011b m\u016f\u017ee m\u00edt plech z nerezov\u00e9 oceli du\u00e1ln\u00ed certifikaci 304\/304H, proto\u017ee m\u00e1 dostate\u010dn\u00fd obsah uhl\u00edku, aby splnil po\u017eadavek 304H (minim\u00e1ln\u011b 0,040%) a tak\u00e9 spl\u0148uje po\u017eadavky na velikost zrna a pevnost 304H, existuje 316\/<a href=\"https:\/\/wldstainless.com\/materials\/austenitic-stainless-steel\/316-316l-stainless-steel\/\">316L<\/a> a dal\u0161\u00ed dvoj\u00ed t\u0159\u00eddy nerezov\u00e9 oceli.<\/p>\n<p>Nejd\u016fle\u017eit\u011bj\u0161\u00ed je rozd\u00edl v karbonu a v\u00fdsledn\u00e1 pevnost. Uhl\u00edk je \u00fa\u010dinn\u00fd austenitick\u00fd stabiliza\u010dn\u00ed prvek a lze jej pova\u017eovat za ne\u010distotu nebo leguj\u00edc\u00ed prvek, kter\u00fd zlep\u0161uje pevnost nerezov\u00e9 oceli, zejm\u00e9na p\u0159i vysok\u00fdch teplot\u00e1ch. Obsah uhl\u00edku ve v\u011bt\u0161in\u011b austenitick\u00fdch nerezov\u00fdch ocel\u00ed je pod 0,02% ~ 0,04%. Aby byla po sva\u0159ov\u00e1n\u00ed dobr\u00e1 odolnost proti korozi, je obsah uhl\u00edku v nerezov\u00e9 oceli s n\u00edzk\u00fdm obsahem uhl\u00edku \u0159\u00edzen pod 0,030%. Aby se zlep\u0161ila pevnost p\u0159i vysok\u00fdch teplot\u00e1ch, vysok\u00fd obsah uhl\u00edku nebo uhl\u00edku t\u0159\u00eddy \u201eH\u201c je udr\u017eov\u00e1n na hodnot\u011b 0,041 TP3T nebo m\u00edrn\u011b vy\u0161\u0161\u00ed.<\/p>\n<p>Men\u0161\u00ed atomy uhl\u00edku v plo\u0161n\u011b centrovan\u00e9 krychlov\u00e9 struktu\u0159e jsou v m\u0159\u00ed\u017ekov\u00fdch mezer\u00e1ch mezi v\u011bt\u0161\u00edmi atomy Cr, Ni a Mo, kter\u00e9 omezuj\u00ed disloka\u010dn\u00ed pohyb, br\u00e1n\u00ed deformaci ta\u017enosti a zpev\u0148uj\u00ed nerezovou ocel. Za podm\u00ednek zvy\u0161uj\u00edc\u00ed se teploty, jako je proces sva\u0159ov\u00e1n\u00ed, m\u00e1 uhl\u00edk silnou tendenci sr\u00e1\u017eet chrom v matrici z nerezov\u00e9 oceli s karbidem bohat\u00fdm na chrom a druh\u00e1 f\u00e1ze m\u00e1 tendenci sr\u00e1\u017eet se na hranici zrn sp\u00ed\u0161e ne\u017e ve st\u0159edu zrna, tak\u017ee karbid chr\u00f3mu je snadno se tvo\u0159\u00ed na hranici zrn.<\/p>\n<p>Chrom je nezbytn\u00fd prvek pro zv\u00fd\u0161en\u00ed odolnosti nerezov\u00e9 oceli proti korozi, ale karbid chr\u00f3mu je z matrice nerezov\u00e9 oceli odstran\u011bn, tak\u017ee odolnost proti korozi je zde hor\u0161\u00ed ne\u017e u zbytku matrice nerezov\u00e9 oceli. Zv\u00fd\u0161en\u00ed obsahu uhl\u00edku m\u016f\u017ee roz\u0161\u00ed\u0159it teplotn\u00ed rozsah, tak\u017ee se zkr\u00e1t\u00ed doba senzibilizace nebo ztr\u00e1ty odolnosti proti korozi, sn\u00ed\u017een\u00ed obsahu uhl\u00edku m\u016f\u017ee odd\u00e1lit nebo \u00fapln\u011b zabr\u00e1nit tvorb\u011b karbidu p\u0159i sva\u0159ov\u00e1n\u00ed. T\u0159\u00eddy s n\u00edzk\u00fdm obsahem uhl\u00edku, jako je 304L a 316L, obsah uhl\u00edku ni\u017e\u0161\u00ed ne\u017e 0,030%, obsah uhl\u00edku u v\u011bt\u0161iny vysoce legovan\u00fdch druh\u016f austenitu, jako je nerezov\u00e1 ocel 6%Mo, je ni\u017e\u0161\u00ed ne\u017e 0,020%. Pro kompenzaci poklesu pevnosti v d\u016fsledku poklesu obsahu uhl\u00edku se n\u011bkdy p\u0159id\u00e1v\u00e1 dal\u0161\u00ed interstici\u00e1ln\u00ed prvek dus\u00edk pro zpevn\u011bn\u00ed nerezov\u00e9 oceli.<\/p>\n<p>Dvojit\u00e1 nerezov\u00e1 ocel m\u00e1 jak vysokou pevnost konven\u010dn\u00ed nerezov\u00e9 oceli, tak odolnost v\u016f\u010di korozi ultra n\u00edzkouhl\u00edkov\u00e9 nerezov\u00e9 oceli. M\u016f\u017ee vy\u0159e\u0161it probl\u00e9m slab\u00e9ho v\u00fdkonu svarov\u00e9ho spoje v\u011bt\u0161iny austenitick\u00e9 nerezov\u00e9 oceli, byl \u0161iroce pou\u017e\u00edv\u00e1n v za\u0159\u00edzen\u00edch n\u00edzkoteplotn\u00edch p\u0159ij\u00edmac\u00edch stanic LNG a potrub\u00ed s velk\u00fdm pr\u016fm\u011brem. Cena du\u00e1ln\u00ed nerezov\u00e9 oceli je v z\u00e1sad\u011b stejn\u00e1 jako u ultran\u00edzkouhl\u00edkov\u00e9 nerezov\u00e9 oceli. Nyn\u00ed n\u011bkolik \u010d\u00ednsk\u00fdch ocel\u00e1ren m\u016f\u017ee dod\u00e1vat t\u0159\u00eddy pro vysp\u011bl\u00fd trh, jak\u00fdkoli z\u00e1jemce n\u00e1s pros\u00edm kontaktujte.<\/p>\n<p>&nbsp;<\/p>","protected":false},"excerpt":{"rendered":"<p>Austenitick\u00e9 nerezov\u00e9 oceli jsou nejroz\u0161\u00ed\u0159en\u011bj\u0161\u00ed nerezov\u00e9 oceli, kter\u00e9 p\u0159edstavuj\u00ed asi 751 TP3T celkov\u00e9 spot\u0159eby nerezov\u00e9 oceli. Rychl\u00fd rozvoj chemick\u00e9ho pr\u016fmyslu a petrochemick\u00e9ho pr\u016fmyslu klade vy\u0161\u0161\u00ed po\u017eadavky na korozn\u00ed odolnost a pevnost nerezov\u00e9 oceli. Nap\u0159\u00edklad nerezov\u00e1 ocel 304\/304L dvoj\u00ed jakosti znamen\u00e1, \u017ee m\u00e1 [\u2026]<\/p>","protected":false},"author":1,"featured_media":2146,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23],"tags":[],"class_list":["post-2144","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\/2144","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=2144"}],"version-history":[{"count":3,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts\/2144\/revisions"}],"predecessor-version":[{"id":2148,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts\/2144\/revisions\/2148"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/media\/2146"}],"wp:attachment":[{"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/media?parent=2144"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/categories?post=2144"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/tags?post=2144"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}