臺灣博碩士論文加值系統

本研究係以熱機控制製程鋼板(TMCP sheet)經潛弧銲接(SAW)後之銲接件為素料，先檢驗其銲道品質及量測其性能，含成分分析、機械性能、殘留應力、熱膨脹係數及金相顯微組織觀察等，以評估其銲接性；隨後探討銲後熱處理(PWHT)及銲後特殊處理(PWST)兩種應力消除方式，再對銲接件進行性能測試及顯微組織觀察，以評估兩者之優劣性及實用性。研究結果顯示：TMCP鋼板組織均勻、晶粗細緻且具有良好的等向機性；經潛弧銲接後，因並無裂紋及缺陷存在，致其抗拉強度與素料者相當且接合效率佳，說明銲接件品質良好且穩定。在應力消除方面，傳統的PWHT試樣由於銲道中央產生明顯的軟化現象，整體應力峰值和強度均下降且均勻的分佈，易造成毫微孔洞多、細且廣的擴散型斷裂模式；另外在本文中所研發的PWST試樣，除了具有經濟且快速的實用價值外，更具有最佳的接合效率η值(96%)和最低的降伏比YR值(82%)，亦更能提高TMCP鋼板之抗震性和耐蝕性。

The aim of this thesis is to evaluate the weldability such as chemical elements, mechanical property, residual stress, coefficient of thermal expansion and microstructure by using the weidment of TMCP sheet after SAW as a raw material. Consequently, PWHT and PWST were empolyed to relieve the residual stress and the effects were compared. The results show that TMCP sheet has good mechanical property with uniform and isotropic microstructures. The tensile strength between weidment and base metal is almost equal and joint efficiency is excellent. The weld quality''s good and stable after SAW joint. The weld bead soften clearly by relieving the residual stress with PWHT. However, the PWST has the best joint efficiency (96%) and the lowest YR (82%). It helps the TMCP sheet improve the performances of earthquake resistance and corrosion resistance.