臺灣博碩士論文加值系統

摘 要
本研究的目的在研究，銲道附近區域溫度場改變對銲件 殘留應力、角變
形及冶金結構的影響。實驗中局部溫度場改 變採用的方法有三：背面加
熱銲接、背面冷卻銲接與正面冷 卻銲接。並選用三種不同材料(AISI304
不銹鋼、SAE1018低碳 鋼及SAE1050中碳鋼板)做比較，以研究材料性質及
材料相變 化對殘留應力及角變形的影響。銲接方法採用自生氬氣電弧
銲接法，殘留應力量測採用ASTM標準E837之鑽孔應變計法， 角變形值採
用平均垂直位移量，冶金分析利用金相與微硬度 來評估。實驗結果顯示
，背面加熱銲接會微幅增加殘留應 力，其原因可能為溫度歷程的包絡
面積增加與淬火效應的作 用減小，背面加熱銲接可以有效降低角變形，
其原因是背面 加熱銲接可降低厚度方向溫差。背面冷卻銲接可使最大主
殘 留應力下降31-67%，可能原因為，溫度歷程的包絡面積減 小、淬
火效應的作用增強與低溫麻田散鐵相變化。背面冷卻 銲接將使304不銹
鋼及1018低碳鋼角變形變大，僅1050中碳鋼 角變形降低，其原因可能
為1050中碳鋼產生麻田散鐵相變化 而抵消了厚度上溫差作用。正面冷卻
銲接對殘留應力並無明 顯差異，其原因可能與正面冷卻銲接會同時減少
溫度歷程之 包絡面積及減少淬火效應有關，正面冷卻銲接在304不銹鋼
， 可降低角變形達47%，其原因可能是304不銹鋼在正面冷卻銲 接過程
會大量減少厚度上溫差有關。背面冷卻銲接、正面冷 卻銲接較一般銲接
在HAZ有較高硬度值，背面加熱銲接會減 少HAZ之硬度。背面加熱銲接
將使熱影響區寬度增加，背面 冷卻銲接的熱影響區縮小，正面冷卻銲
接則影響不大。 關鍵字：銲接、熱循環、相變化、熱應力、殘留應
力、角變 形

ABSTRACT
This paper aimed at the investigation of the effect of local
temperature field changing on residual stress and angular
distortion in weldment. The methods of local temperature
changing include bacdside heat welding (BHW),
backside cool welding (BCW) and upside cool welding (UCW).
In this study , the materials of type 304 stainless steel, 1018
and 1050 carbon steel were used. An autogenous gas
tungsten arc welding was utilized. The residual
stress were determined by using the hole-drilling strain-
gage method of ASTM standard E837. During welding, the thermal
cycle of different locations in weldment were recorded. Optical
microscrope and Vicker's hardness tester were used to evaluate
the metallurgical effect. The experimental results
showed that the residual stress increase with the
increase of the area involved of temqerature history
during welding. The angular distortion decrease with decrease
the temperature difference in the thickness direction near
the seam. In backside cool welding process,
martensite structure was formed in the seam and HAZ in
1050 carbon steel, then the residual stress and angular
distortion were reduced.
Key words : Welding, Thermal cycle, Phase transformation,
Thermal stress, Residual stress, Angular
distortion