Improved Penetration with the Use of Oxide Fluxes in Activated TIG Welding of Low Activation Ferritic/Martensitic Steel
Improved Penetration with the Use of Oxide Fluxes in Activated TIG Welding of Low Activation Ferritic/Martensitic Steel
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DOI：
10.1007/s12666-016-0835-6
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发表时间：
2016-02
影响因子：
1.6
通讯作者：
J. Vora;V. Badheka
中科院分区：
文献类型：
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作者：
J. Vora;V. Badheka
研究了单组分氧化物保护剂对6 mm厚低活化铁素体/马氏体（LAFM）钢TIG焊表面形貌、焊缝形貌、显微组织和显微硬度的影响。在此，自焊TIG焊的一种新变体，其中在焊接之前通过一层薄层施加氧化物粉末，例如CaO、CrO 3、Fe 2 O3、MnO 2、TiO 2和ZnO，以产生板上焊珠接头。试验结果表明，采用CaO、Fe 2 O3、MnO 2、TiO 2、ZnO等活性TIG（A-TIG）工艺，可以提高LAFM钢焊接接头的熔深和焊缝深宽比（D/w）。然而，在相同的焊接条件下，使用焊剂Fe 2 O3和TiO 2，实现了全熔透。因此，有人提出，尽管完全渗透是通过多种机制实现的，但肯定有一种特定的主导机制能够提供更好的上级渗透。此外，考虑到A-TIG工艺的冶金方面，进行维氏显微硬度测试，并使用光学显微镜进行显微组织表征。TIG和A-TIG焊件的显微组织和显微硬度值没有观察到明显的变化。焊缝及热影响区为粗大马氏体和细小马氏体的混合组织。
The present study is to investigate the effects of the single component oxide fluxes in the TIG process on surface appearance, weld morphology, microstructures and micro-hardness during welding of 6 mm thick low activation ferritic/martensitic (LAFM) steel. Herein, a novel variant of the autogenous TIG welding, wherein oxide powders such as CaO, CrO3, Fe2O3, MnO2, TiO2, and ZnO were applied through a thin layer before welding to produce a bead-on-plate joint. Experimental results indicated that activated TIG (A-TIG) process could increase the joint penetration and weld depth-to-width ratio (D/w) of LAFM steel weldment using CaO, Fe2O3, MnO2, TiO2, and ZnO fluxes. However, under same welding conditions, full penetration was achieved with the use of fluxes Fe2O3and TiO2. Accordingly, it was proposed that, there might certainly be a specific dominant mechanism capable of giving superior penetration, although complete penetration was achieved through multiple mechanisms. Additionally to consider the metallurgical respects of A-TIG process, Vickers micro-hardness test was performed and microstructure characterization was carried out using optical microscopy. No noticeable change in microstructure and micro-hardness values of the TIG and A-TIG weldment was observed. A composite mixture of fine and coarse martensite was observed in weld and HAZ region.