5% natriy persulfat eritmasida 50 graduslik titaniumli suv isitgichi uchun, nega persulfat ioni kuchli oksidlovchi bo'lishiga qaramay, titanni passivlashtirmaydi va uning o'rniga transpassiv erishni keltirib chiqaradi?

Na 2 S 2 O 8 ) is a greater oxidiser ( E o = 2.01 V for S 2 O 8 2 - / SO 4 2 - ) than nitric acid . However, on titanium persulfate induces transpassive dissolution, not stable passivation. At 50°C the high oxidation potential moves the titanium surface into the transpassive area (>1,8 V va SCE) bu erda passiv plyonka parchalanadi va titan yiliga 0,2-0,5 mm tezlikda Ti4+ sifatida eriydi.

Korroziya darajasi persulfat konsentratsiyasiga nisbatan (miqdoriy)

Na2S2O8 da 50 gradusda 500 soat:

Persulfat kontsentratsiyasi (%) Korroziya darajasi (mm/yil)Yuz potentsiali (V va SCE) Mexanizm 0 0.005–0.010 0.2–0,5Passiv 1 0.05-0.12 1.2-1.5 Aralash
3 0.12–0.25 1.5–1,7 Transpassivlikning boshlanishi
5 0.20–0.40 1.7–1,9 Transpassiv 10 0.35–0.60 1.8–2,0Transpassiv o‘tishga kuchli transpassiv harorat ta’siri

Harorat (daraja ) 5% Persulfat – Korroziya tezligi (mm/yil)Mexanizmi 25 0.10–0,20 Transpassiv 40 0.15–0,30Transpasiv 50 0.20–0,40Transpassiv 60 0.30–0,60 Kuchli
Muhandislik uchun tavsiya

Transpasif eritma tufayli titan persulfat eritmalari uchun tavsiya etilmaydi. PTFE bilan qoplangan isitgichlar yoki tantaldan foydalaning. Titan haroratlarda ishlatilishi kerak<30°C and persulfate should be limited to <2% if it must be used. The engineer can choose the right materials by knowing the transpassive behaviour of the persulfate.