{"id":20197,"date":"2020-12-11T08:29:20","date_gmt":"2020-12-11T08:29:20","guid":{"rendered":"https:\/\/www.meetyoucarbide.com\/?p=20197"},"modified":"2020-12-11T08:31:42","modified_gmt":"2020-12-11T08:31:42","slug":"main-problems-encountered-in-welding-of-18cr-austenitic-stainless-steel","status":"publish","type":"post","link":"https:\/\/www.meetyoucarbide.com\/tr\/18cr-ostenitik-paslanmaz-celigin-kaynaginda-karsilasilan-ana-sorunlar\/","title":{"rendered":"18cr \u00d6stenitik Paslanmaz \u00c7eliklerin Kayna\u011f\u0131nda Kar\u015f\u0131la\u015f\u0131lan Temel Sorunlar"},"content":{"rendered":"

\u00d6stenitik paslanmaz \u00e7elik, y\u00fcksek krom i\u00e7eri\u011fi ve yo\u011fun oksit filmi nedeniyle iyi bir korozyon direncine sahiptir. Cr18% ve Ni8% i\u00e7erildi\u011finde tek bir \u00f6stenit yap\u0131s\u0131 elde edilebilir. Bu nedenle \u00f6stenitik paslanmaz \u00e7elik, iyi korozyon direncine, plastisiteye, y\u00fcksek s\u0131cakl\u0131k performans\u0131na ve kaynak performans\u0131na sahiptir. Bununla birlikte, farkl\u0131 \u00e7al\u0131\u015fma ko\u015fullar\u0131 alt\u0131nda, \u00f6stenitik paslanmaz \u00e7elik kaynak ba\u011flant\u0131lar\u0131 genellikle, taneler aras\u0131 korozyon, stres korozyonu, b\u0131\u00e7ak korozyonu, kaynak s\u0131cak \u00e7atlaklar\u0131, \u03b1 faz\u0131 gevrekli\u011fi ve benzeri gibi yap\u0131 kusurlar\u0131na neden olmas\u0131 kolay olan baz\u0131 \u00f6zel problemlerle kar\u015f\u0131 kar\u015f\u0131yad\u0131r.<\/p>

Kaynakl\u0131 ba\u011flant\u0131lar\u0131n korozyon analizi<\/h2>

Kaynakl\u0131 ba\u011flant\u0131lar\u0131n taneler aras\u0131 korozyonu<\/h3>

Taneler aras\u0131 korozyon, \u00f6stenitik paslanmaz \u00e7eli\u011fin en \u00f6nemli korozyon problemlerinden biridir. Taneler aras\u0131 korozyon meydana geldi\u011finde, ciddi oldu\u011funda g\u00fcc\u00fc neredeyse kaybedecek ve belirli bir stres uyguland\u0131\u011f\u0131nda taneler aras\u0131 k\u0131r\u0131lma meydana gelecektir. \u00d6stenitik paslanmaz \u00e7elik kaynak ba\u011flant\u0131s\u0131n\u0131n taneler aras\u0131 korozyonuna esas olarak krom karb\u00fcr \u00e7\u00f6keltmesi neden olur. \u00d6stenitik paslanmaz \u00e7elik, 500 ~ 800 \u2103 s\u0131cakl\u0131k aral\u0131\u011f\u0131nda duyarl\u0131 hale getirildi\u011finde, a\u015f\u0131r\u0131 doymu\u015f kat\u0131 \u00e7\u00f6zelti karbonunun taneler aras\u0131 s\u0131n\u0131ra dif\u00fczyon h\u0131z\u0131, kromunkinden daha h\u0131zl\u0131d\u0131r ve a\u015f\u0131r\u0131 doymu\u015f kat\u0131 \u00e7\u00f6zeltideki karbon, tane yak\u0131n\u0131nda krom ile birle\u015ftirilir. B\u00f6lgedeki krom i\u00e7eri\u011fi pasivasyon i\u00e7in gerekli olan limit i\u00e7eri\u011fin (w (CR) 12.5%) alt\u0131na d\u00fc\u015ft\u00fc\u011f\u00fcnde b\u00f6lgenin korozyonu h\u0131zlanacak ve taneler aras\u0131 korozyon olu\u015facakt\u0131r. Sonu\u00e7lar, HAZ'\u0131n hassasla\u015ft\u0131r\u0131lm\u0131\u015f s\u0131cakl\u0131k b\u00f6lgesindeki taneler aras\u0131 korozyonun, tepe \u0131s\u0131tma s\u0131cakl\u0131\u011f\u0131n\u0131n 600 \u2103 ile 1000 \u2103 aras\u0131nda oldu\u011fu b\u00f6lgede meydana geldi\u011fini g\u00f6stermektedir. Taneler aras\u0131 korozyonun nedeni, hala \u00f6stenit tane s\u0131n\u0131r\u0131nda krom karb\u00fcr\u00fcn \u00e7\u00f6kelmesidir. Taneler aras\u0131 korozyonu azaltmak ve \u00f6nlemek i\u00e7in ana \u00f6nleyici tedbirler \u015funlar\u0131 i\u00e7erir:<\/strong><\/p>

\u2460 K\u00fc\u00e7\u00fck \u00f6zellikler (k\u00fc\u00e7\u00fck ak\u0131m, y\u00fcksek kaynak h\u0131z\u0131) ve \u00e7ok pasolu kaynak benimsenmi\u015ftir;<\/p>

\u2461 Ana metal ve kaynak malzemesindeki karbon i\u00e7eri\u011fi m\u00fcmk\u00fcn oldu\u011funca azalt\u0131lmal\u0131 ve C i\u00e7eri\u011fi 0.03%'den az olan kaynak malzemesi kullan\u0131lmal\u0131d\u0131r;<\/p>

\u2462 Sonu\u00e7 olarak, Cr, ostenit tane s\u0131n\u0131r\u0131ndaki zay\u0131f krom olgusunu azaltan, ferritte ostenite g\u00f6re daha h\u0131zl\u0131 tane s\u0131n\u0131r\u0131na yay\u0131l\u0131r;<\/p>

\u2463 \u00c7elik ve kaynak malzemelerinde karbona kromdan daha g\u00fc\u00e7l\u00fc afiniteye sahip Ti, Nb ve di\u011fer elementlerin eklenmesi, karbon ba\u011f\u0131 ile kararl\u0131 bile\u015fikler olu\u015fturabilir, b\u00f6ylece \u00f6stenit tane s\u0131n\u0131rlar\u0131nda krom t\u00fckenmesini \u00f6nleyebilir.<\/p>

Kaynakl\u0131 ba\u011flant\u0131lar\u0131n gerilim korozyonu<\/h3>

Paslanmaz \u00e7eli\u011fin gerilmeli korozyon \u00e7atlamas\u0131 en zararl\u0131 korozyon davran\u0131\u015f\u0131d\u0131r. \u00c7atlama s\u0131ras\u0131nda deformasyon olmaz. Kaza genellikle ani olur ve sonu\u00e7lar\u0131 ciddidir. \u00c7eli\u011fin bile\u015fimi, yap\u0131s\u0131 ve durumu, ortam\u0131n t\u00fcr\u00fc, s\u0131cakl\u0131k, konsantrasyon, stres \u00f6zellikleri, boyut ve yap\u0131sal \u00f6zellikler dahil olmak \u00fczere hizmet ko\u015fullar\u0131 alt\u0131nda paslanmaz \u00e7eli\u011fin gerilme korozyon \u00e7atlamas\u0131n\u0131 etkileyen bir\u00e7ok fakt\u00f6r vard\u0131r.<\/p>

\"\"<\/figure>

Gerilme korozyonunu azaltmak ve \u00f6nlemek i\u00e7in ba\u015fl\u0131ca \u00f6nlemler \u015funlard\u0131r:<\/p>

\u2460 G\u00fc\u00e7l\u00fc montaj, mekanik darbe ve ark yanmas\u0131ndan ka\u00e7\u0131n\u0131n, so\u011fuk i\u015f deformasyonunu ve stresi azalt\u0131n;<\/p>

\u2461 Ortamdaki ve ortamdaki safs\u0131zl\u0131klar\u0131 (\u00f6zellikle klor\u00fcr, flor\u00fcr vb.) s\u0131k\u0131 bir \u015fekilde kontrol edin;<\/p>

\u2462 Makul malzeme se\u00e7imi (ana metal, kaynak malzemesi): tane irile\u015fmesini ve martensit yap\u0131s\u0131n\u0131 sertle\u015ftirmeyi \u00f6nleyin;<\/p>

\u2463 Kaynak, herhangi bir gerilim konsantrasyonu (alttan kesme gibi) olmadan iyi \u015fekillendirilmi\u015ftir;<\/p>

\u2464 Stresi azaltmak i\u00e7in kaynak s\u0131ras\u0131n\u0131 makul bir \u015fekilde d\u00fczenleyin;<\/p>

\u2465 Korozyon \u00f6nleyici i\u015flem: kaplama, astar veya katodik korumaya korozyon \u00f6nleyici ekleyin.<\/p>

 <\/h2>

Kaynakl\u0131 ba\u011flant\u0131lar\u0131n s\u0131cak \u00e7atlak hassasiyet analizi<\/h2>

\u00d6stenitik paslanmaz \u00e7eli\u011fin s\u0131cak \u00e7atlaklar\u0131, esas olarak, kaynak metalinin s\u0131v\u0131 metalinin kat\u0131la\u015fma i\u015flemi s\u0131ras\u0131nda \u00fcretilen kristal \u00e7atlaklard\u0131r. Bu zamanda, birincil kristaller \u00f6tektik erime noktas\u0131nda, esas olarak dendritler aras\u0131nda bulunur. Ana nedenler a\u015fa\u011f\u0131daki gibidir:<\/p>

\u2460 S, P, C ve benzeri, Ni ile d\u00fc\u015f\u00fck erime noktal\u0131 \u00f6tektik olu\u015fturur (\u00f6rne\u011fin, NIS + Ni'nin erime noktas\u0131 644 \u2103'dir), bu da tane s\u0131n\u0131r\u0131 kuvvetini zay\u0131flat\u0131r;<\/p>

\u2461 \u00d6stenitik paslanmaz \u00e7elik, likidus ve solidus aras\u0131nda b\u00fcy\u00fck mesafe, uzun kristalle\u015fme s\u00fcresi, g\u00fc\u00e7l\u00fc dendrit oryantasyonu ve safs\u0131zl\u0131k elementlerinin ayr\u0131lmas\u0131n\u0131n kolay \u00fcretilmesi gibi avantajlara sahiptir;<\/p>

\u2462 \u00c7eli\u011fin \u0131s\u0131l iletkenli\u011fi k\u00fc\u00e7\u00fckt\u00fcr ve do\u011frusal genle\u015fme katsay\u0131s\u0131 b\u00fcy\u00fckt\u00fcr, bu nedenle stres \u00fcretmek kolayd\u0131r.<\/p>

\"\"<\/figure>

\"\" <\/h2>

S\u0131cak \u00e7atlaklar\u0131n kaynaklanmas\u0131n\u0131 \u00f6nlemek i\u00e7in ana \u00f6nlemler \u015funlar\u0131 i\u00e7erir:<\/h3>

\u2460 Adi metal ve kaynak malzemesindeki zararl\u0131 k\u00fck\u00fcrt ve fosfor safs\u0131zl\u0131klar\u0131n\u0131n i\u00e7eri\u011fi s\u0131k\u0131 bir \u015fekilde kontrol edilecektir;<\/p>

\u2461 Kaynakta, \u00f6stenit s\u00fctunlu kristalin y\u00f6n\u00fcn\u00fc bozan yakla\u015f\u0131k 5% ferrit \u00fcretilir;<\/p>

\u2462 K\u00fc\u00e7\u00fck ak\u0131m ve h\u0131zl\u0131 kaynak i\u015flemi benimsenmi\u015ftir.<\/p>

Kaynakl\u0131 ba\u011flant\u0131larda ferrit i\u00e7eri\u011finin kontrol\u00fc<\/h2>

\u00d6stenitik \u00e7eli\u011fin kaynak metalindeki ferrit i\u00e7eri\u011fi, sadece \u03b1 (\u03c3) faz gevrekli\u011finin olu\u015fumu ve termal mukavemeti ile ilgili de\u011fildir, ayn\u0131 zamanda eklemin s\u0131cak \u00e7atlama direncini de do\u011frudan etkiler. Is\u0131tma s\u00fcresi ne kadar uzun olursa, y\u00fcksek s\u0131cakl\u0131kta kalma s\u00fcresi o kadar uzun olur, daha fazla ya\u011f\u0131\u015f, eklemin mekanik \u00f6zelliklerini ciddi \u015fekilde etkiler. S\u0131cak \u00e7atlama direnci a\u00e7\u0131s\u0131ndan, kaynak metalinde belirli bir miktar ferrit gereklidir. Ancak, \u03b1 faz\u0131 gevrekli\u011fi ve termal dayan\u0131m g\u00f6z \u00f6n\u00fcne al\u0131nd\u0131\u011f\u0131nda, ferrit i\u00e7eri\u011fi ne kadar d\u00fc\u015f\u00fckse o kadar iyidir. Bu nedenle, y\u00fcksek s\u0131cakl\u0131k dayan\u0131ml\u0131 kaynakl\u0131 ba\u011flant\u0131lar i\u00e7in ferrit i\u00e7eri\u011fi s\u0131k\u0131 bir \u015fekilde kontrol edilmelidir. Baz\u0131 durumlarda \u00f6stenitik kaynak metali kullan\u0131lmal\u0131d\u0131r.<\/p>

\"\"<\/figure>

<\/p><\/div>","protected":false},"excerpt":{"rendered":"

Austenitic stainless steel has good corrosion resistance because of its high chromium content and dense oxide film. When Cr18% and Ni8% are contained, a single austenite structure can be obtained. Therefore, austenitic stainless steel has good corrosion resistance, plasticity, high temperature performance and welding performance. However, under different working conditions, austenitic stainless steel welding joints…<\/p>","protected":false},"author":2,"featured_media":20201,"comment_status":"closed","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"_jetpack_memberships_contains_paid_content":false,"footnotes":""},"categories":[79],"tags":[],"class_list":["post-20197","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-materials-weekly"],"jetpack_featured_media_url":"https:\/\/www.meetyoucarbide.com\/wp-content\/uploads\/2020\/12\/\u56fe\u72479.png","jetpack_sharing_enabled":true,"_links":{"self":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/posts\/20197","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/comments?post=20197"}],"version-history":[{"count":0,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/posts\/20197\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/media\/20201"}],"wp:attachment":[{"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/media?parent=20197"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/categories?post=20197"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.meetyoucarbide.com\/tr\/wp-json\/wp\/v2\/tags?post=20197"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}