17-4PH 和 455不銹鋼銲接性分析

Study of Welding Capability the 17-4PH and 455 Stainless Steel

施聖瑋(Sheng-Wei Shih)

指導教授 ： 趙志燁

國立屏東科技大學/工學院/機械工程系所/碩士(2009年)

https://doi.org/10.6346/NPUST.2009.00196

摘要

本主要研究17-4PH和455不銹鋼合金，分析在不同溫度熱處理條件的機械性質，探討其異種銲接後銲道與熱影響區之顯微結構，以及建立適當的熱處理條件，以改善銲接構件之性能。其研究成果如下：
455不銹鋼在830-1200℃不同高溫/1小時後，其晶粒大小D=0.25T-283。由拉伸試驗顯示，晶粒大於0.72μm，合金呈現脆化現象，其間強度與晶粒大小關係為：σ=σ0+55D-½，晶粒大小隨著溫度的上升而變大，強度則下降。
455不銹鋼經固溶830℃/1小時，於時效480-600℃/4-16小時，其間抗拉強度、降伏強度與延伸率，分別為165-309.9 ksi、157.8-300.8 ksi與6.84-20%。合金經固溶980℃/1小時，於480-600℃/4-16小時，其間抗拉強度、降伏強度與延伸率，分別為168-246.4 ksi、158-239.1與4.6-19.38%。17-4PH不銹鋼經固溶1040℃/1小時於480℃-600℃之抗拉強度、降伏強度與延伸率，分別為162-208.3 ksi、160-203ksi與11.68-18.8%。
當455不銹鋼與17-4PH兩種母材各自固溶後再進行銲接，於525℃/4H時效後，發生脆斷，從TEM分析得知在455不銹鋼熱影響區與銲道間除有α相析出外，亦有ω相之結構析出，而產生易脆的結構。當兩母材先銲接後再進行980℃/1H固溶+525℃/4H時效，除改善了17-4PH強度不足問題，亦改善銲道裂紋的問題。

關鍵字

異種銲接 ； 455不銹鋼 ； 17-4PH

並列摘要

The main 17-4PH and 455 stainless steel alloy. Analysis of heat treatment in different conditions of temperature mechanical properties. To explore the Dissimilar welding with post weld heat affected zone microstructure. And the creation of appropriate conditions of heat treatment. To improve the performance of welded components. The results of their research are as follows：
455 stainless steel at different temperature 830-1200℃/1 hour. Its grain size D=0.25T-283.By the tensile test showed that the grain is greater than 0.72μm alloy showed the phenomenon of embrittlement. During this period the relationship between strength and grain size as: σ = σ0 +55 D-½, grain size increases as the temperature changes and decreased strength.
455 stainless steel by Solution heat treatment(SHT) 830℃/1 hours aging in 480-600℃/4-16 hours, during which the tensile strength, yield strength and elongation, respectively 165-309.9 ksi ,157.8-300.8 ksi and 6.84 - 20%.SHT on 980℃/1 hours, at 480-600℃/4-16 hours, during which the tensile strength, yield strength and elongation, respectively 168-246.4 ksi ,158-239.1 ksi and 4.6-19.38%.17-4PH stainless steel SHT on 1040℃/1 hours of 480℃-600℃ tensile strength, yield strength and elongation, respectively 162-208.3 ksi ,160-203ksi and 11.68-18.8%.
When 455 and 17-4PH stainless steel materials of their respective two SHT after welding, at 525℃/4H aging, the occurrence of brittle fracture. From TEM analysis that the 455 stainless steel in the heat affected zone and the weld between the addition to α-phase precipitates, but also the structure of ω-phase precipitates, which have a fragile structure. When the two materials after welding to 980℃/1H SHT + 525℃/4H aging,in addition to improved strength 17-4PH problem, also to improve the problem of weld cracks.

並列關鍵字

Dissimilar Welding ； 455 Stainless Steel ； 17-4PH

參考文獻

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