304不?鋼構材環境腐蝕及銅合金閥組件破損機制之研究

Study on the Mechanism of Environmental Corrosion and Failure for 304 Stainless Steel and Copper Alloy Valve Sets

馬克平(Ke-Ping Ma)

指導教授 ： 于劍平

崑山科技大學/工程學院/機械工程研究所/碩士(2008年)

摘要

船舶使用之不?鋼構材與銅合金閥組本體零組件，長時間受海水及複雜應力作用，常會發生嚴重腐蝕及破裂之情況。故本文係針對這些腐蝕及破損現象，對其發生機制，作一有系統的研究探討。
構材部份係以304L不?鋼材所製作之水下排煙系統管路及水櫃加強材，因長期處於海水腐蝕環境中，分析研究304L不?鋼材質承受複雜應力腐蝕之破損研究。而零組件部份，分別選用304材質所製成之滑油泵穩梢螺栓及青銅材質所製成之柴油隔艙閥破壞作一研究探討與分析。實驗首先將長期使用於水下環境之排煙系統管路、水櫃肋材、滑油泵穩梢螺栓及船舶艙間柴油系統用隔艙閥之破損構件，分別裁取適當尺度之試件，藉由X-ray、PT非破壞檢驗、金相顯微組織觀察、硬度實驗、腐蝕生成物機制研究、分光分析儀成分分析及利用SEM進行破斷面形貌觀察與EDS元素成分分析等實驗。
根據實驗結果分析由304L不?鋼材所製作之水下排煙系統管路及水櫃加強材，因長期於含氯化物之海水環境、內燃機排煙含硫化物影響、微生物腐蝕與受海水非線性或儎具於航行時承受不同湧浪反覆應力等作用下，發生嚴重應力腐蝕破損之現象。另滑油泵穩梢螺栓及柴油系統用柴油隔艙閥，因零組件所處環境，均受長期拉伸或反覆應力之影響，造成疲勞破斷或裂縫。本研究期能確切判斷各破損件之破損原因，並藉研究結果提供相關產業於水面載具構件設計及材質選用之參考。

關鍵字

304不?鋼 ； 沿晶腐蝕 ； 氯化物 ； 應力腐蝕 ； 微生物腐蝕

並列摘要

The structure materials of stainless steel and parts of copper alloy valve sets, employed to ship, were usually occurred by serious conditions of corrosion and fracture when they had immersed the sea and endured complex stress for a long time. Therefore, the systemic investigation of mechanism for the corrosion and fracture is employed in this study.
The structure material of under water exhaust system and water tank reinforced material was made by 304L stainless steel and stayed in the seawater for a long time. The failure of 304L stainless steel endured complex stress corrosion was investigated in this study. The failures of slip-oil pump steady pin bolt and slip-oil separated valve made by copper alloy for the part of component was studied and analysis.
In the experiment of this study, the failure structures of pipeline of exhaust system, rib material of water tank, slip-oil steady pin bolt and slip-oil separated valve made by copper alloy under water were cut individual with suit size for specimen. The X-ray, PT non-fracture detection, observation of metal micro-structure, hardness test, element spectrometer, SEM and EDS were used to investigate the mechanism of corrosion and failure.
Based on the experimental results, the structure material of under water exhaust system and water tank reinforced material made by 304L stainless steel will induce serious stress corrosion failure because of staying in the seawater with chloride corrosion, the effect of internal combustion exhaust system with sulfur corrosion, microbiologically influenced corrosion, the corrosion of action of non-linear complex stress or platform of ship endure the vary forces from different sea-wave.
On the other hand, the slip-oil steady pin bolt and slip-oil system separated tank valve were endured by action of tension or repeated stress, and then the fatigue and fracture failure will be occurred. In this study, the exact reasons of failure parts were found, and based on the results, we can support the reference of design ship and the material selection method.

並列關鍵字

304 stainless steel ； Intergranular corrosion ； Chloride ； Stress corrosion ； Microbiologically influenced corrosion

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