熱軋鋼捲帶狀銹蝕改善

The Improvement of Banded Rust in Hot Rolled Coil

趙泉隆(Chuan Lung Chao)

《鑛冶：中國鑛冶工程學會會刊》 42卷2期 (1998/06) Pp. 105-110

https://doi.org/10.30069/MM.199806_42(2).0010

摘要

帶狀銹蝕其銹蝕部位經由彎曲試驗、粗糙度量測、X-光繞射、腐蝕電位量測、SEM及水質化驗等分析，研判銹蝕區應是因冷卻水水量過度集中該區域而產生過冷的現象，該區域由於銹皮延性較差，易於軋延過程破裂，導致銹皮組織較不緻密（即較鬆脫），易含水而致銹。於精軋區的冷卻水水量過度集中的原因有精軋前除銹箱除銹水柱間重疊區過寬、第一、二座軋機後除銹水及機座間冷卻水噴嘴掉落、機座間冷卻水及水幕式冷卻之水壓不均、工輥冷卻水擋水板破裂等，彼此之間若有重疊，則過冷的效應將更大，另該過冷帶於盤捲區盤捲過程因該區漏水將會更嚴重。製程改善分治標與治本兩方面同時進行，治標為消除水壓不均因素及避免加成效應，治本為減少FSB所產生紅黑痕之黑痕寬度及改善精軋區、盤捲區漏水問題，經此一連串改善動作，確實獲得有效改善。

關鍵字

腐蝕電位 ； 精軋除銹箱 ； 噴頭 ； 噴嘴 ； 水幕式冷卻系統

並列摘要

The stained area of banded rust which is analyed by roughness measurement、bend test、X-ray diffraction、corrosion potential、SEM and water quality analysis is regarded as the overcooling phenomena due to accumulation of cooling water. The scale characteristics is less plastic and easily broken during rolling process. So scale density is decreased causing it to absorb water easily and to get stained. In finish mill section, the causes that produce overload of cooling water include overwide water spray in FSB, dropped nozzles of interstand cooling heads, uneven water pressure distribution of interstand & WCIC cooling system and the cracked wiper of work roll. If there are overlap between them, then overcooling effect would be bigger. The overcooling area will be more serious during cooling process due to the leak in the down coiler. The processing improvement include temporal and permanent methods. Temporality is to minimize uneven water pressure and avoid the adding effect. Permanence is to decrease the leak from finish mill and down coiler sections.

並列關鍵字

Corrosion potential ； FSB ； Head ； Nozzle ； WCIC