The Influence of Pulsed Arc and Electromagnetic Vibration on Microstructure and Properties of Super Stainless Steel Weld Metal

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Project title

Code/計畫編號

NSC102-2221-E019-008-MY3

Translated Name/計畫中文名

脈衝電弧及電磁振動對超級不銹鋼銲道金屬微觀結構及性質之效應

Project Coordinator/計畫主持人

Shing-Hoa Wang

Funding Organization/主管機關

National Science and Technology Council

Department/Unit

Department of Mechanical and Mechatronic Engineering

Website

https://www.grb.gov.tw/search/planDetail?id=8122190

Year

2014

Start date/計畫起

01-08-2014

Expected Completion/計畫迄

01-07-2015

Bugetid/研究經費

1417千元

ResearchField/研究領域

材料科技
機械工程

歐洲瑞典Sandvik公司開發出的超級雙相不鏽鋼SAF2507及超級高鉬奧斯田254SMO不鏽鋼，習知缺點為銲道常因熱熔接後，造成過多δ-肥粒鐵生成，適當比例之奧斯田相不足，導致銲道失去其原本母材之優越抗孔蝕性及一般抗蝕性。故多採以高氮合金之填料線材或氬氣保護氣體中添加0.1vol% ~ 15vol% 之N2成分混合氣措施實施銲接，彌補氮之損失，避免抗蝕性優越的奧斯田相匱之。本研究異於傳統，在無N2添加下試圖利用電磁振動及脈衝電弧結合活性劑輔助熔融穿深方式，開發提升達45 vol% ~ 50vol%含量之gamma奧斯田相，並探討其呈核機制和抗孔蝕性。本研究將以3年的時間完成，第一年：探討電磁振動誘發較高奧斯田相分率製程及各種物性。第二年：施加電弧脈衝配合前第一年之較佳結果，改善奧斯田相形態、分佈體積分率製程與各種物性。第三年：添加活性助銲劑，改善第一年及第二年不足，開發出完美的奧斯田相形態、分佈體積分率、機械性質及抗孔蝕性的銲接微觀組織，增進石化業、動力廠和冷凍業之結構材料使用效益。本計畫同時與日本國立National Institute for Material Science(NIMS)研究院合作，利用全世界獨一無二的Advanced Electrothermal Mechanical Testing System (ETMT)設備，從事銲道金屬In-situ相變態及miniature size的疲勞特性分析及熱穩定性探討。期盼本計畫3年後開發出無需添加N2的製備方法，創新抗孔蝕性與機械性均卓越之銲道微觀結構組織，提昇超級不鏽鋼銲接結構於嚴酷環境應用之品質與保固。 It is well known that the weld metal of super duplex stainless steel SAF2507 and high Mo content of super austenitic 254SMO developed by Europe Sweden Sandvik often causes excessive δ-ferrite after welding. The weld metal results in an inappropriate proportion of austenitic phase and losses its superior property of pitting and general corrosion resistance as original base metal. Generally either the filler wire with high N content or the Ar shielding gas mixed with adding 0.1vol% ~ 15vol% N2 is used to make up for the loss of nitrogen in the weld metal, thus prevent from weakening corrosion resistance. This study is different from the traditional way. Instead of conventional N addition, an alternative new way by using the electro- magnetic vibration and pulsed arc TIG welding combined of the active flux perform to develop a super stainless steel weld metal having the content of up to 45 vol% ~ 50vol% gamma austenitic phase. In the mean time, the nucleation mechanism of gamma formation and anti-pitting without N addition will be studied. This project will be completed within three years. The goal of first year is to investigate the electro- magnetic vibration induced higher austenitic phase fraction process and various physical properties. The goal of second year is to apply the pulsed arc for improving the former year results in austenitic phase morphology, distribution and the volume fraction and a variety of physical properties. The goal of third year is to add active flux to improve the weld metal from the previous two years results and made an optimum welded microstructure for the petrochemical industry, power plants and refrigeration industry. A unique worldwide equipment of Advanced Electrothermal Mechanical Testing System (ETMT) from the Japan National Institute for Material Science (NIMS) will be allowed to use in cooperation with this project to engage in the In-situ weld metal phase transformation and fatigue characteristics of the miniature sized weld metal. It is expected that this three-year project can a good microstructure of super stainless weld metal with anti-pitting and excellent mechanical properties to meet the requirement of the harsh environment application without using conventional N additional process.

Keyword(s)

超級雙相鋼
脈衝電弧
電磁振動
相變態
孔蝕
Super duplex stainless steel
pulsed arc
electromagnetic vibrations
phase transformation
pitting

DSpace CRIS

The Influence of Pulsed Arc and Electromagnetic Vibration on Microstructure and Properties of Super Stainless Steel Weld Metal

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