Titan qoplamali isitgichda ishlov berish natijasida yuzadan temirning ifloslanishi (10 Ng/Sm² Vs. 100 Ng/Cm²) ochiq{2}}kontakning potentsial siljishini va 60 darajada 1% NaCl da yoriqlar korroziyasini boshlash vaqtini qanday o'zgartiradi?
Xabar QOLDIRISH
Surface iron contamination on titanium heaters creates local galvanic cells. Iron particles are more noble than titanium in chloride solutions. At low contamination (10 ng/cm²), open-circuit potential (OCP) drifts slowly (-0.05 V over 500 hours) and crevice corrosion initiates after >2000 soat. Yuqori ifloslanishda (100 ng/sm²) OCP tez siljiydi (100 soat ichida -0,2 V) va yoriqlar korroziyasi 200-500 soat ichida boshlanadi.
Miqdoriy OCP Drift va Yoriq boshlanishi
2-darajali titanium uchun 60 darajada 1% NaCl da:
| Temirning ifloslanishi (ng/sm²) | OCP Drift (V va Ag/AgCl) 100 soatdan keyin | Yoriqni boshlash vaqti (soat) | 1000 soatdan keyin maksimal chuqurlik chuqurligi (µm) |
|---|---|---|---|
| 0 (toza) | 0 dan -0,02 gacha | >5,000 | 0 |
| 10 | -0,02 dan -0,05 gacha | 2,000–4,000 | 10–30 |
| 25 | -0,05 dan -0,10 gacha | 1,000–2,000 | 20–60 |
| 50 | -0,10 dan -0,15 gacha | 500–1,000 | 50–100 |
| 100 | -0,15 dan -0,25 gacha | 200–500 | 100–200 |
| 200 | -0,25 dan -0,40 gacha | 100–200 | 150–300 |
Xlorid konsentratsiyasining temirning tajovuzkorligiga ta'siri
| NaCl konsentratsiyasi (%) | Dazmol 50 ng/sm² – Boshlash vaqti (soat) | Toza sirtni boshlash (soat) |
|---|---|---|
| 0.5 | 1,000–2,000 | >5,000 |
| 1.0 | 500–1,000 | >5,000 |
| 3.0 | 200–500 | 2,000–4,000 |
| 5.0 | 100–300 | 1,000–2,000 |
Sirtni tozalash va tekshirish bo'yicha qo'llanma
| Kontaminatsiya darajasi (ng/sm²) | Tavsiya etilgan tozalash usuli | Tozalashdan keyin OCP (V va Ag/AgCl) |
|---|---|---|
| <10 (clean) | Yo'q | -0,05 dan -0,10 gacha |
| 10–50 | Ishqoriy yog'sizlantirish + kislotali tuzlangan | -0,05 dan -0,10 gacha |
| 50–100 | Azot kislotasi (20%, 50 daraja, 10 min) | -0,05 dan -0,10 gacha |
| >100 | Nitrik-HF tuzlangan + elektropolish | -0,05 dan -0,10 gacha |
Muhandislik bo'yicha tavsiya
Xlorid xizmatidagi titanli isitgichlar uchun temirning maksimal ifloslanishini 10 ng/sm² belgilang. 20% nitrat kislota bilan 50 daraja haroratda 10 daqiqa davomida tozalang. Tozalashdan keyin OCPni o'lchash; agar OCP Ag/AgCl ga nisbatan -0,10 V dan ortiq salbiy bo'lsa, qayta tozalang. Yuzaki temirni nazorat qilish orqali muhandis OCPning siljishi va yoriqlar korroziyasini oldini oladi.
