{"id":6207,"date":"2026-09-25T19:52:35","date_gmt":"2026-09-25T16:52:35","guid":{"rendered":"https:\/\/www.defencemetal.com\/index.php\/2026\/09\/25\/aisi-329-aisi-318-farki\/"},"modified":"2026-09-30T10:43:01","modified_gmt":"2026-09-30T07:43:01","slug":"aisi-329-aisi-318-farki","status":"publish","type":"post","link":"https:\/\/www.defencemetal.com\/index.php\/2026\/09\/25\/aisi-329-aisi-318-farki\/","title":{"rendered":"AISI 329 ile AISI 318 Aras\u0131ndaki Fark Nedir?"},"content":{"rendered":"

AISI 329<\/strong> ve AISI 318<\/strong> ikisi de dubleks paslanmaz \u00e7eliktir — yani yap\u0131lar\u0131 yar\u0131 \u00f6stenit, yar\u0131 ferrittir. Aralar\u0131ndaki fark bir ku\u015fak fark\u0131d\u0131r: 329 ilk nesil dubleks, 318 ise bug\u00fcn\u00fcn standard\u0131 olan azotla ala\u015f\u0131mland\u0131r\u0131lm\u0131\u015f<\/strong> dubleksdir.<\/p>\n

Azot neyi de\u011fi\u015ftirdi?<\/h3>\n

\u0130lk nesil dubleksler kaynakta sorun \u00e7\u0131kar\u0131yordu. Uluslararas\u0131 Molibden Birli\u011fi’nin (IMOA) dubleks imalat k\u0131lavuzu bunu a\u00e7\u0131k\u00e7a anlat\u0131r: bu kalitelerde kayna\u011f\u0131n \u0131s\u0131dan etkilenen b\u00f6lgesi a\u015f\u0131r\u0131 ferritle\u015fti\u011fi i\u00e7in toklu\u011fu d\u00fc\u015f\u00fck, korozyon direnci ise ana metalden belirgin \u015fekilde zay\u0131f kal\u0131yordu.<\/em><\/p>\n

\u00c7\u00f6z\u00fcm azot oldu. IMOA’ya g\u00f6re azot ala\u015f\u0131mland\u0131rmas\u0131, kaynak sonras\u0131 \u0131s\u0131dan etkilenen b\u00f6lgenin toklu\u011funu ve korozyon direncini ana metale yakla\u015ft\u0131r\u0131r ve zararl\u0131 intermetalik fazlar\u0131n olu\u015fum h\u0131z\u0131n\u0131 d\u00fc\u015f\u00fcr\u00fcr. Penn Stainless de ayn\u0131 noktay\u0131 vurguluyor: bug\u00fcn\u00fcn dublekslerindeki y\u00fcksek azot, a\u015f\u0131r\u0131 ferrit olu\u015fumunu \u00f6nlemeye yar\u0131yor.<\/p>\n

Pratik sonu\u00e7: AISI 318 teslim halinde kaynaklanabilir bir dublekstir; AISI 329 ayn\u0131 anlamda de\u011fildir.<\/strong><\/p>\n

Bile\u015fimdeki fark<\/h3>\n

329 (1.4460) daha y\u00fcksek kromlu ama daha d\u00fc\u015f\u00fck molibdenlidir. 318 (1.4462) kromdan biraz feragat edip molibdeni neredeyse iki kat\u0131na \u00e7\u0131kar\u0131r<\/strong> ve azotu \u015fartnameye sokar. \u00c7ukurcuk korozyonu a\u00e7\u0131s\u0131ndan belirleyici olan da budur.<\/p>\n

Rakamlarla kar\u015f\u0131la\u015ft\u0131rma<\/h3>\n

De\u011ferler EN 10088-3 d\u00f6k\u00fcm analizi s\u0131n\u0131rlar\u0131 ve \u00e7\u00f6zeltiye al\u0131nm\u0131\u015f (+AT) \u00e7ubuk i\u00e7in verilmi\u015ftir.<\/p>\n

\n\n\n\n\n\n\n\n\n\n\n\n\n\n\n
\u00d6ZELL\u0130K<\/th>\nAISI 329 (1.4460)<\/th>\nAISI 318 (1.4462)<\/th>\n<\/tr>\n<\/thead>\n
Karbon (C)<\/td>\nmax %0,05<\/td>\nmax %0,030<\/td>\n<\/tr>\n
Silisyum (Si)<\/td>\nmax %1,00<\/td>\nmax %1,00<\/td>\n<\/tr>\n
Mangan (Mn)<\/td>\nmax %2,00<\/td>\nmax %2,00<\/td>\n<\/tr>\n
Fosfor (P)<\/td>\nmax %0,035<\/td>\n—<\/td>\n<\/tr>\n
Krom (Cr)<\/td>\n%25,00 – 28,00<\/td>\n%21,00 – 23,00<\/td>\n<\/tr>\n
Nikel (Ni)<\/td>\n%4,50 – 6,50<\/td>\n%4,50 – 6,50<\/td>\n<\/tr>\n
Molibden (Mo)<\/strong><\/td>\n%1,30 – 2,00<\/strong><\/td>\n%2,50 – 3,50<\/strong><\/td>\n<\/tr>\n
Akma (Rp0,2)<\/td>\n\u2265 450 MPa<\/td>\n\u2265 450 MPa<\/td>\n<\/tr>\n
Kopma uzamas\u0131<\/td>\n\u2265 %20<\/td>\n\u2265 %25<\/td>\n<\/tr>\n
Sertlik<\/td>\n\u2264 260 HB<\/td>\n—<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n

PREN: \u00e7ukurcuk direnci g\u00f6stergesi<\/h3>\n

Dublekslerde yayg\u0131n kullan\u0131lan g\u00f6sterge PREN = %Cr + 3,3 × %Mo + 16 × %N<\/strong> form\u00fcl\u00fcd\u00fcr. AISI 318 i\u00e7in yay\u0131mlanan de\u011ferler 31 ile 35 aras\u0131nda de\u011fi\u015fir — ve bu da\u011f\u0131l\u0131m \u00f6zensizlik de\u011fil, ger\u00e7ek bir \u015fartname fark\u0131d\u0131r (a\u015fa\u011f\u0131ya bak\u0131n\u0131z).<\/p>\n

IMOA ve Outokumpu ikisi de ayn\u0131 uyar\u0131y\u0131 yap\u0131yor: PREN yaln\u0131zca bir g\u00f6stergedir, tasar\u0131m de\u011feri de\u011fildir. Azotun katsay\u0131s\u0131 da kaynaktan kayna\u011fa 16, 22 veya 30 al\u0131nabiliyor. Teklif kar\u015f\u0131la\u015ft\u0131r\u0131rken hangi form\u00fcl\u00fcn kullan\u0131ld\u0131\u011f\u0131n\u0131 sorun.<\/p>\n

\u00dcst s\u0131cakl\u0131k s\u0131n\u0131r\u0131: dublekslerin unutulan tavan\u0131<\/h3>\n

Dubleksler y\u00fcksek s\u0131cakl\u0131k \u00e7eli\u011fi DE\u011e\u0130LD\u0130R. AISI 318 i\u00e7in yay\u0131mlanan \u00fcst servis s\u0131cakl\u0131\u011f\u0131 yakla\u015f\u0131k 280 – 316 °C<\/strong> band\u0131ndad\u0131r (Alleima 280 °C, Industeel 280 °C, Outokumpu ASME II-D onay\u0131 316 °C, Macsteel 300 °C). Sebebi mekanik de\u011fil metalurjiktir: ferrit faz\u0131nda alfa-prime \u00e7\u00f6kelmesi ve daha yukar\u0131da sigma faz\u0131 toklu\u011fu d\u00fc\u015f\u00fcr\u00fcr.<\/p>\n

Sipari\u015f verirken dikkat<\/h3>\n
\n

Bu iki malzemenin isimleri, sekt\u00f6r\u00fcn en kar\u0131\u015f\u0131k b\u00f6lgesidir.<\/p>\n

“AISI 318” asl\u0131nda bir AISI g\u00f6sterimi de\u011fildir.<\/strong> ASTM A240’ta Tip 318 diye bir kalite yoktur. “318” ve “318LN” Avrupa piyasas\u0131n\u0131n 1.4462 i\u00e7in kulland\u0131\u011f\u0131 lakaplard\u0131r; ger\u00e7ek g\u00f6sterim UNS S31803 \/ S32205<\/strong> ve EN 1.4462<\/strong>‘dir. Sertifikaya “AISI 318” yazd\u0131rmay\u0131n.<\/p>\n

1.4460’\u0131n UNS kar\u015f\u0131l\u0131\u011f\u0131nda be\u015f kurulu\u015f be\u015f farkl\u0131 cevap veriyor:<\/strong> Ugitech S31200, Rodacciai S32950, METALCOR \/ Langley Alloys \/ Sverdrup Steel ise S32900 diyor. Bile\u015fimler de ayn\u0131 de\u011fildir — EN 1.4460 azotla ala\u015f\u0131mland\u0131r\u0131lm\u0131\u015ft\u0131r ve nikeli daha y\u00fcksektir; ASTM S32900’de azot \u015fart\u0131 yoktur. Sipari\u015f ve sertifikada malzeme numaras\u0131n\u0131 (1.4460) esas al\u0131n.<\/strong><\/p>\n

S31803 ile S32205 ayn\u0131 \u015fey de\u011fildir.<\/strong> S32205 krom, molibden ve azotun \u00fcst band\u0131n\u0131 hedefler. Langley Alloys’un ifadesiyle: S32205’e g\u00f6re \u00fcretilmi\u015f malzeme S31803’\u00fc tam olarak kar\u015f\u0131lar, tersi do\u011fru de\u011fildir. IMOA da azot alt s\u0131n\u0131r\u0131n\u0131n %0,14 olmas\u0131n\u0131n g\u00fcvenilir kaynakl\u0131 imalat i\u00e7in gerekli oldu\u011funu belirtiyor.<\/p>\n<\/div>\n

Kaynak<\/h3>\n

AISI 318 iyi kaynaklan\u0131r: \u00f6n \u0131s\u0131tma gerekmez, kaynak sonras\u0131 \u0131s\u0131l i\u015flem normalde gerekmez. Ancak dubleks ilave metal kullan\u0131lmal\u0131d\u0131r<\/strong> (2209 \/ E2209 \/ ER2209) — \u00f6stenitik ilave metal do\u011fru sonu\u00e7 vermez. Pasolar aras\u0131 s\u0131cakl\u0131k 150 °C’nin alt\u0131nda tutulur.<\/p>\n

G\u00f6sterimler, standartlar ve AMS kar\u015f\u0131l\u0131klar\u0131<\/h3>\n

Ayn\u0131 \u00e7elik, hangi sistemde konu\u015ftu\u011funuza g\u00f6re farkl\u0131 isimle an\u0131l\u0131r. Sipari\u015f ve sertifika kar\u0131\u015f\u0131kl\u0131klar\u0131n\u0131n \u00e7o\u011fu buradan \u00e7\u0131kar, o y\u00fczden k\u0131saca \u00f6zetleyelim:<\/p>\n