鋼骨箱型柱與內橫隔板T形電熱熔渣銲道接合品質研究

Quality Assessments on T-Shape Electro-Slag Welds (ESWs) of Internal Diaphragm to Box-Column Plate

林克強(Ker-Chun Lin) ； 莊勝智(Sheng-Jhih Jhuang) ； 李昭賢(Chao-Hsien Li) ； 林志翰(Chih-Han Lin)

《結構工程》 30卷2期 (2015/06) Pp. 23-38

https://doi.org/10.6849/SE.201506_30(2).0002

摘要

電熱熔渣銲（Electro-slag Welds，ESW）為鋼骨箱型柱製作柱內橫隔板最有效率的銲接方法之一，因此台灣鋼骨建築結構之箱型柱構件，廣泛使用ESW做為柱內橫隔板與柱板接合之銲接方法。過去有關實尺寸鋼骨箱型柱之梁柱接合，對應柱內橫隔板與柱板採ESW銲接之接合者，經統計約超過25%之柱板與柱內橫隔板間ESW銲道接合，發生非預期性的脆性破壞，造成其梁柱接合在未充分發展非線性變形前即發生脆性斷裂。由破壞面之巨觀金相照片觀察發現，ESW銲道偏移導致部分熔填不足，為造成此破壞的主要因素。本文針對箱型柱柱板與內橫隔板ESW銲接接合之力學特性、製作程序、與超音波檢測技術等進行研究，結果顯示，由於ESW銲接入熱量極高，導致熱量在不易消散之柱板側母材熱影響區（heat affected zone, HAZ）發生顯著脆化現象，同時也發現，現行ESW銲道製作程序無法穩定地獲得預期的銲道品質，此可藉由適當的非破壞超音波試驗法，採用正確的檢驗程序與合理的檢測標準進行檢測，得以經濟的方法獲得可確保的銲道品質。因此本文也提出一套完整且適用於鋼骨箱型柱中柱板與橫隔板ESW銲道接合的製作細節、超音波檢測程序與檢測標準，以排除箱型柱內柱板與橫隔板ESW銲道接合的製作偏移，而造成部分銲道熔透不足的現象發生，以提升鋼骨箱型柱內橫隔板ESW銲道的製作品質，達到確保其梁柱接合能滿足規範要求之變形能力。

關鍵字

鋼骨箱型柱 ； 電熱熔渣銲 ； 橫隔板 ； 超音波檢測 ； 熱影響區 ； 沙丕凹槽韌性 ； 硬度

並列摘要

The welding procedure of electro-slag welds (ESW) is one of the most efficient welding methods for a T-shape joint of internal diaphragm to column plate of steel box column. Therefore, it is widely used to steel building structures in order to save making time of steel structure fabrication shop in Taiwan. Unfortunately, according to the past research results on beam-to-column connection with the box column, there was at least 25% fractured probability of ESWs joints, join internal diaphragm to column plate of the box column, to occur unacceptably premature brittle-fracture before its beam end's plastic hinge not developing. Based on observation of macro metallurgical photos from the past studies, local inadequate melting due to welds bias is one of the most important factors to result in this failure mode. To prevent the ESW from fracture in the beam-to-column connection, this research focused on mechanical characteristics of ESW and near parts, fabrication procedure of the existing ESW in Taiwan and ultrasonic testing (UT) technology. The research results indicated that the ESW joint between internal diaphragm and column plate of the box column due to its high heat-input caused heat affected zone (HAZ) on base metal of the column plate brittle under its slow heat-dissipation from the column plate. In addition, the existing ESW technology can't be effectively controlled and obtain stable quality of welds. However, the UT is a feasible and most economic nondestructive method to inspect the ESW welds. This research proposed an integral UT inspection technology include inspecting sensors, procedure and acceptable criteria. A fabricated detail also was advised in this paper to prevent the ESW from local inadequate melting. The proposed technologies of fabrication and inspection can not only effectively ensure the ESW quality but also significantly increase seismic performance of the steel beam-to-box column connections.

並列關鍵字

steel box column ； electro-slag welds (ESW) ； diaphragm ； ultrasonic testing (UT) ； heat affected zone (HAZ) ； Charpy V-notch (CVN) toughness ； hardness