tailieunhanh - Handbook Corrosion (1992) WW Part 6

Tham khảo tài liệu 'handbook corrosion (1992) ww part 6', kỹ thuật - công nghệ, cơ khí - chế tạo máy phục vụ nhu cầu học tập, nghiên cứu và làm việc hiệu quả | Lithium is somewhat more aggressive to plain carbon steels that sodium or sodium-potassium. As a result low-alloy steels should not be considered for long-term use above 300 C 570 F . At higher temperatures the ferritic stainless steels show better results at higher temperatures. Cadmium. Low-alloy steels exhibit good serviceability to 700 C 1290 F . Zinc. Most engineering metals and alloys show poor resistance to molten zinc and carbon steels are no exception. Antimony. Low-carbon steels have poor resistance to attack by antimony. Mercury. Although plain carbon steels are virtually unattacked by mercury under nonflowing or isothermal conditions the presence of either a temperature gradient or liquid flow can lead to drastic attack. The corrosion mechanism seems to be one of dissolution with the rate of attack increasing rapidly with temperature above 500 C 930 F . Alloy additions of chromium titanium silicon and molybdenum alone or in combination show resistance to 600 C 1110 F . Where applicable the attack of ferrous alloys by mercury can be reduced to negligible amounts by the addition of 10 ppm Ti to the mercury this raises the useful range of operating temperatures to 650 C 1200 F . Additions of metal with a higher affinity for oxygen than titanium such as sodium or magnesium may be required to prevent oxidation of the titanium and loss of the inhibitive action. Aluminum. Plain carbon steels are not satisfactory for long-term containment of molten aluminum. Gallium is one of the most aggressive of all liquid metals and cannot be contained by carbon or low-alloy steels at elevated temperatures. Indium. Carbon and low-alloy steels have poor resistance to molten indium. Lead Bismuth Tin and Their Alloys. Low-alloy steels have good resistance to lead up to 600 C 1110 F to bismuth up to 700 C 1290 F and to tin only up to 150 C 300 F . The various alloys of lead bismuth and tin are more aggressive. Weathering Steels . Coburn Corrosion Consultants Inc. Yong-Wu Kim