Rau Titanium Heat Qws Immersed Nyob rau hauv 0.5% Hydrofluoric Acid tov nrog 2% Nitric Acid ntawm 40 degree, Qhov ratio ntawm HNO₃ rau HF (2: 1 Vs . 5}: 1) Hloov Corrosion Morphology Los ntawm Pitting mus rau Uniform Thinning?
Tso lus
Hauv kev sib xyaw ntawm hydrofluoric (HF) thiab nitric (HNO₃) acids, qhov piv ntawm HNO₃ rau HF txiav txim siab txog kev txhim kho corrosion. Ntawm qhov sib piv qis (2: 1, piv txwv li, 1% HF + 2% HNO₃), pitting dominates vim tsis tiav passivation. Ntawm qhov sib piv siab (5: 1, piv txwv li, 1% HF + 5% HNO₃), cov txheej txheem thinning dominates vim tias cov oxidizing nitrate zaj duab xis tiv thaiv kev tawg hauv cheeb tsam.
Quantitative Corrosion Morphology vs. HNO₃/HF Ratio
Ntawm 40℃nrog 0.5% HF, sib txawv HNO₃:
| HNO ₃/HF Ratio | HNO ₃ (%) | Corrosion Rate (mm / xyoo) | Morphology | Pitting Ceev (qhov / cm²) |
|---|---|---|---|---|
| 1:1 | 0.5 | 0.8–1.5 | Pitting hnyav | 100–300 |
| 2:1 | 1.0 | 0.5–1.0 | Pitting | 50–150 |
| 3:1 | 1.5 | 0.3–0.6 | Mixed | 10–50 |
| 4:1 | 2.0 | 0.2–0.4 | Uniform nyias | 5–20 |
| 5:1 | 2.5 | 0.15–0.30 | Hnav khaub ncaws | <5 |
| 10:1 | 5.0 | 0.10–0.20 | Hnav khaub ncaws | 0 |
Cov nyhuv ntawm qhov kub thiab txias ntawm Morphology hloov pauv
| Kub (degree) | Yam tsawg kawg HNO₃/HF rau Uniform Corrosion | Pom zoo Ratio |
|---|---|---|
| 25 | 3:1 | 4:1 |
| 40 | 4:1 | 5:1 |
| 50 | 5:1 | 6:1 |
| 60 | 6:1 | 8:1 |
Acid Ratio Control Guide
| Xav Morphology | Pom zoo HNO₃/HF Ratio | Cia siab tias Corrosion Rate (mm / xyoo) | Qib pom zoo |
|---|---|---|---|
| Pitting (tsis txhob) | <3:1 | >0.5 | Tsis pom zoo |
| Mixed | 3–4:1 | 0.3–0.6 | Qib 7 |
| Uniform (tau txais) | 4–5:1 | 0.2–0.4 | Qib 7 |
| Uniform (zoo) | >5:1 | <0.2 | Qib 7 |
Kev pom zoo engineering
Hauv HF / HNO₃ pickling da dej, tuav HNO₃ / HF piv saum toj no 5: 1 kom ua tau zoo corrosion tsis zoo li pitting. Siv Qib 7 titanium kom txhim kho kev tiv thaiv. Los ntawm kev tswj cov kua qaub piv, tus kws ua haujlwm hloov cov txheej txheem corrosion los ntawm pitting mus rau qhov zoo sib xws ntawm thinning.
