{"id":2167,"date":"2021-07-15T06:50:11","date_gmt":"2021-07-15T06:50:11","guid":{"rendered":"https:\/\/wldstainless.com\/?p=2167"},"modified":"2021-07-15T06:54:20","modified_gmt":"2021-07-15T06:54:20","slug":"nickel-austenitic-stainless-steel-grades","status":"publish","type":"post","link":"https:\/\/wldstainless.com\/cs\/nickel-austenitic-stainless-steel-grades\/","title":{"rendered":"Nikl austenitick\u00e9 nerezov\u00e9 oceli"},"content":{"rendered":"

O niklu je zn\u00e1mo, \u017ee je drah\u00fdm leguj\u00edc\u00edm prvkem a je nezbytn\u00fd v n\u011bkter\u00fdch aplikac\u00edch, kde je vy\u017eadov\u00e1na jak odolnost proti korozi pod nap\u011bt\u00edm, tak austenitov\u00e1 struktura. Nap\u0159\u00edklad odolnost proti te\u010den\u00ed je d\u016fle\u017eit\u00e1 v prost\u0159ed\u00ed s vysokou teplotou, kde je austenitick\u00e1 nerezov\u00e9 oceli<\/a> jsou pot\u0159eba. Podobn\u011b jako u tradi\u010dn\u00edch austenitick\u00fdch nerezov\u00fdch ocel\u00ed je dvojit\u00e1 hranice v\u00fdznamn\u00fdm rysem austenitick\u00fdch nerezov\u00fdch ocel\u00ed bohat\u00fdch na nikl, proto\u017ee m\u00e1 ni\u017e\u0161\u00ed energii p\u0159i vrstven\u00ed. Austenitick\u00e9 nerezov\u00e9 oceli jsou n\u00e1chyln\u00e9 k prask\u00e1n\u00ed koroz\u00ed nap\u011bt\u00edm (SCC). Odolnost proti korozi pod nap\u011bt\u00edm se v\u0161ak v\u00fdrazn\u011b zlep\u0161\u00ed, kdy\u017e obsah niklu p\u0159ekro\u010d\u00ed 20%. Studuje se vliv niklu na intenzitu nap\u011bt\u00ed prahov\u00e9 koroze nap\u011bt\u00ed (105\u2103, 22% vodn\u00fd roztok NaCl) ve slitin\u00e1ch Fe-Ni-Cr obsahuj\u00edc\u00edch chrom 16%~21%. Austenitick\u00e1 nerezov\u00e1 ocel bohat\u00e1 na nikl (NiASS) m\u016f\u017ee b\u00fdt pova\u017eov\u00e1na za samostatnou t\u0159\u00eddu nerezov\u00e9 oceli. Ve skute\u010dnosti je odolnost dvouf\u00e1zov\u00fdch a feritov\u00fdch nerezov\u00fdch ocel\u00ed proti korozi p\u0159i nap\u011bt\u00ed srovnateln\u00e1 s odolnost\u00ed dvouf\u00e1zov\u00fdch a feritov\u00fdch nerezov\u00fdch ocel\u00ed, pokud obsah niklu p\u0159ekro\u010d\u00ed 30%. N\u011bkolik omezen\u00fdch druh\u016f austenitu bohat\u00e9ho na nikl nerezov\u00e9 oceli<\/a> jsou uvedeny v tabulce n\u00ed\u017ee. Super austenitick\u00e9 nerezov\u00e9 oceli 254SMO a 654SMO jsou navr\u017eeny speci\u00e1ln\u011b pro ropn\u00fd a plyn\u00e1rensk\u00fd pr\u016fmysl. Typick\u00fdmi aplikacemi jsou chlazen\u00ed mo\u0159skou vodou, b\u011blen\u00ed buni\u010diny a hydraulick\u00e1 a p\u0159\u00edstrojov\u00e1 potrubn\u00ed za\u0159\u00edzen\u00ed.<\/p>\n

 <\/p>\n

Ni-austenitick\u00e9 nerezov\u00e9 oceli<\/strong><\/p>\n\n\n\n\n\n\n\n\n\n\n\n\n\n
Slitina<\/td>\nC<\/td>\nSi<\/td>\nMn<\/td>\nCr<\/td>\nNi<\/td>\nMo<\/td>\nW<\/td>\nspol<\/td>\nCu<\/td>\nNb<\/td>\nN<\/td>\n<\/tr>\n
254SMo<\/td>\n0.01<\/td>\n0.8<\/td>\n1.0<\/td>\n20<\/td>\n18<\/td>\n6.1<\/td>\n<\/td>\n<\/td>\n0.7<\/td>\n<\/td>\n0.2<\/td>\n<\/tr>\n
654SMo<\/td>\n0.01<\/td>\n<\/td>\n3.5<\/td>\n24<\/td>\n22<\/td>\n7.3<\/td>\n<\/td>\n<\/td>\n0.5<\/td>\n<\/td>\n0.5<\/td>\n<\/tr>\n
Sanicro 25<\/td>\n0.1<\/td>\n0.2<\/td>\n0.5<\/td>\n22.5<\/td>\n25<\/td>\n<\/td>\n3.6<\/td>\n3.5<\/td>\n3.0<\/td>\n0.5<\/td>\n0.23<\/td>\n<\/tr>\n
Sanicro 28<\/td>\n0.02<\/td>\n0.6<\/td>\n2.0<\/td>\n27<\/td>\n31<\/td>\n3.5<\/td>\n<\/td>\n<\/td>\n1.0<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
Slitina 800<\/td>\n0.07<\/td>\n0.6<\/td>\n0.6<\/td>\n20.5<\/td>\n30.5<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
353 mA<\/td>\n0.05<\/td>\n1.6<\/td>\n1.5<\/td>\n25<\/td>\n35<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n0.16<\/td>\n<\/tr>\n
Slitina 825<\/td>\n0.03<\/td>\n0.5<\/td>\n0.8<\/td>\n20<\/td>\n38.5<\/td>\n2.6<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
Slitina 625<\/td>\n0.03<\/td>\n0.5<\/td>\n0.5<\/td>\n21<\/td>\nBal<\/td>\n8.5<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
Slitina 690<\/td>\n0.02<\/td>\n0.5<\/td>\n0.5<\/td>\n30<\/td>\n60<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/td>\n<\/tr>\n
Slitina 600<\/td>\n0.05<\/td>\n0.4<\/td>\n0.8<\/td>\n16.5<\/td>\nBal<\/td>\n<\/td>\n<\/td>\n<\/td>\n0.5<\/td>\n<\/td>\n<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n

SANICRO 25, slitina 22Cr-25Ni, je ur\u010dena pro pou\u017eit\u00ed v kotl\u00edch do 700 \u00b0C. Je to materi\u00e1l vhodn\u00fd pro p\u0159eh\u0159\u00edv\u00e1ky a p\u0159ih\u0159\u00edv\u00e1ky d\u00edky sv\u00e9 dobr\u00e9 pevnosti p\u0159i te\u010den\u00ed a odolnosti proti vysok\u00e9 teplot\u011b. Ve skute\u010dnosti je pevnost p\u0159i te\u010den\u00ed SANICRO 25 lep\u0161\u00ed ne\u017e u v\u011bt\u0161iny austenitick\u00fdch nerezov\u00fdch ocel\u00ed v rozsahu 600~750\u2103. Ve vysoce korozivn\u00edm kysel\u00e9m prost\u0159ed\u00ed je Sanicro 28 obvykle nejlep\u0161\u00ed volbou. Pou\u017e\u00edv\u00e1 se p\u0159i vrt\u00e1n\u00ed studn\u00ed s vysokou intenzitou s potrub\u00edm, pl\u00e1\u0161t\u011bm a oblo\u017een\u00edm kysel\u00fdm plynem a dal\u0161\u00ed aplikace zahrnuj\u00ed oh\u0159\u00edva\u010de, \u010derpac\u00ed syst\u00e9my a \u010derpadla a n\u00e1doby v mokr\u00fdch z\u00e1vodech na v\u00fdrobu kyseliny fosfore\u010dn\u00e9 a z\u00e1vodech na super kyselinu fosfore\u010dnou.<\/p>\n

Slitina 800 se \u010dasto pou\u017e\u00edv\u00e1 v prost\u0159ed\u00ed s teplotou od 550 do 1100 \u2103, co\u017e vy\u017eaduje vynikaj\u00edc\u00ed odolnost proti te\u010den\u00ed, dobrou odolnost proti vysokoteplotn\u00ed korozi a pevnost materi\u00e1l\u016f p\u0159i vysok\u00fdch teplot\u00e1ch. Tyto slitiny se tak\u00e9 pou\u017e\u00edvaj\u00ed ve vstupn\u00edch a v\u00fdstupn\u00edch kan\u00e1lech v\u00fdroby \u010dpavku, metanolu a civiln\u00edho plynu, stejn\u011b jako v trubk\u00e1ch pec\u00ed pou\u017e\u00edvan\u00fdch p\u0159i v\u00fdrob\u011b vinylchloridu a etylenu. Mezi dal\u0161\u00ed aplikace pat\u0159\u00ed teplosm\u011bnn\u00e9 trubky a radia\u010dn\u00ed trubky pro fluidn\u00ed spalovac\u00ed lo\u017ee a \u010d\u00e1sti pec\u00ed pro tepeln\u00e9 zpracov\u00e1n\u00ed, jako jsou tlumi\u010de hluku a ochrann\u00e1 pouzdra pro termo\u010dl\u00e1nky.<\/p>\n

Slitina 25Cr-35Ni 353Ma je navr\u017eena pro pou\u017eit\u00ed v krakovac\u00edch pec\u00edch a reformovac\u00edch trubk\u00e1ch, kde jsou zpracov\u00e1v\u00e1ny syntetick\u00e9 plyny v prost\u0159ed\u00ed, kde je nauhli\u010dov\u00e1n\u00ed a absorpce dus\u00edku potenci\u00e1ln\u011b problematick\u00e9. A\u010dkoli existuj\u00ed jin\u00e9 alternativy, kter\u00e9 obsahuj\u00ed v\u00edce chromu, 353 MA je nejlep\u0161\u00ed volbou. Jedn\u00edm z d\u016fvod\u016f je, \u017ee obsahuje prvek Ce, kter\u00fd pom\u00e1h\u00e1 vytv\u00e1\u0159et velmi stabiln\u00ed povrchovou oxidovou vrstvu.<\/p>\n

Alloy 690 obsahuje 60 procent niklu a pou\u017e\u00edv\u00e1 se p\u0159edev\u0161\u00edm v potrub\u00ed parogener\u00e1tor\u016f v jadern\u00fdch elektr\u00e1rn\u00e1ch. Provozn\u00ed teplota je 365 \u2103, p\u0159i kter\u00e9 je potenci\u00e1ln\u00edm probl\u00e9mem korozn\u00ed trhlina mezi zrny. Za dan\u00fdch provozn\u00edch podm\u00ednek je slitina 690 t\u00e9m\u011b\u0159 bez koroze, co\u017e z n\u00ed \u010din\u00ed preferovanou slitinu.<\/p>\n

\"\"<\/p>\n

Je zaj\u00edmav\u00e9 poznamenat, \u017ee austenitick\u00e1 nerezov\u00e1 ocel 254SMO bohat\u00e1 na nikl se pou\u017e\u00edv\u00e1 tak\u00e9 pro um\u011bn\u00ed. Socha \u201eGod, Over the Rainbow\u201c od Carla Millese byla instalov\u00e1na v roce 1995 na ji\u017en\u00edm pob\u0159e\u017e\u00ed Nak Strand ve Stockholmu. Socha je vysok\u00e1 asi 23 metr\u016f a je zn\u00e1m\u00fdm sc\u00e9nick\u00fdm m\u00edstem, kde denn\u011b proplouv\u00e1 velk\u00e9 mno\u017estv\u00ed n\u00e1mo\u0159n\u00edk\u016f. Okoln\u00ed mo\u0159sk\u00e1 voda obsahuje s\u016fl, chlorid velmi snadno zp\u016fsobuje povrchovou korozi, vysoce pevn\u00e1 superaustenitick\u00e1 nerezov\u00e1 ocel 254SMO je do tohoto prost\u0159ed\u00ed velmi vhodn\u00e1.<\/p>","protected":false},"excerpt":{"rendered":"

O niklu je zn\u00e1mo, \u017ee je drah\u00fdm leguj\u00edc\u00edm prvkem a je nezbytn\u00fd v n\u011bkter\u00fdch aplikac\u00edch, kde se vy\u017eaduje jak odolnost proti korozi pod nap\u011bt\u00edm, tak austenitov\u00e1 struktura. Nap\u0159\u00edklad odolnost proti te\u010den\u00ed je d\u016fle\u017eit\u00e1 v prost\u0159ed\u00ed s vysokou teplotou, kde jsou pot\u0159eba austenitick\u00e9 nerezov\u00e9 oceli. Podobn\u011b jako u tradi\u010dn\u00edch austenitick\u00fdch nerezov\u00fdch ocel\u00ed je dvojit\u00e1 hranice v\u00fdznamn\u00fdm prvkem [\u2026]<\/p>","protected":false},"author":1,"featured_media":2171,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[1],"tags":[],"class_list":["post-2167","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-social-activities"],"aioseo_notices":[],"_links":{"self":[{"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts\/2167","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=2167"}],"version-history":[{"count":3,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts\/2167\/revisions"}],"predecessor-version":[{"id":2172,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/posts\/2167\/revisions\/2172"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/media\/2171"}],"wp:attachment":[{"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/media?parent=2167"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/categories?post=2167"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/wldstainless.com\/cs\/wp-json\/wp\/v2\/tags?post=2167"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}