查詢結果分析
來源資料
頁籤選單縮合
題 名 | 鋼胚再加熱區動樑破損原因分析與防治=Fracture Analysis and Prevention of Skid Pipes in the Slab Reheating Furnace |
---|---|
作 者 | 謝榮淵; 潘永村; 魏豐義; | 書刊名 | 材料科學 |
卷 期 | 28:4 1996.12[民85.12] |
頁 次 | 頁261-269 |
分類號 | 440.365 |
關鍵詞 | 趾部; 稀釋作用; 脫碳; 熱影響區; 疲勞破裂; Toe; Dilution; Decarburization; Heat-affected zone; HAZ; Fatique crack; |
語 文 | 中文(Chinese) |
中文摘要 | 本研究之目的在於探討鋼胚再加熱區動樑破裂之原因,首先利用OM、 SEM,及EPMA進行顯微組織、破裂面及元素分析,同時也進行板上單道銲接及 銲後熱處理試驗以模擬銲件之顯微組織。結果顯示,動樑銲接趾部之破裂是因疲 勞所致,其機構為在不�袗�銲道因銲接之稀釋作用而生成硬脆之麻田散鐵組織; 此外,在碳鋼熱影響區因後熱處理及長期使用,碳曾向不�袗�銲道擴散,而造成 脫碳現象,導致肥粒鐵之生成。以上之因素使銲接界面附近產生急劇之硬度變 化,造成應變及應力在界面處集中,誘使微裂縫之生成,又繼續於使用時有反覆 之機械應力作用衍生疲勞破裂。此外,結果也顯示採用鎳基銲材可避免大量麻田 散鐵的產生及銲後熱處理時肥粒鐵之生成,顯著降低銲接界面之硬度差異,應更 有助於破裂之防止。 |
英文摘要 | The purpose of this study is to clarify the cause of fracture for the skid pipes which are located at the preheating zone of reheating furnace. The microstructure of heat-affected zoneand fractrue surface were examined using OM, SEM and EPMA. In addition, the bead-on-plate test was performed and then the specimen subjected to post-weld heat treatment to simulate the microstructure of the weidment. From the fracture analysis by SEM, it was found that the fracture at the toe of weld was caused by fatigue. The fatigue fracture was due to the formation of hard martensite in the stainless weld metal as the result of dilution effect duringwelding. On the other hand, the outward diffusion of carbon occurred from carbon steel tothe weld of stainless steel and the soft ferrite gradually formed near the HAZ of carbon steelduring post-weld heat treatment and operation. Therefore, the marked difference in hardnessacross this interface was developed. It caused stress and strain concentration and led to the formation of microcracks in this interface. After that, the action of cyclic mechanical stressresulted in propagation of the fatigue crack during operation. It was found that nickel-baseelectrode not only greatly to reduce the am out of formatiom of martensite but also prevent from development of ferrite during welding and post-weld heat treatment respectively. The difference in hardness across the welding interface can thereby be significantly reduced, and therefore, of great benefit to the hindering of failure. |
本系統中英文摘要資訊取自各篇刊載內容。