Mechanism of the Development of Marangoni Flow in the Metal Pool Heated by Plasma Arc.

等离子弧加热金属池中马兰戈尼流的发展机制。

• 批准号: 01470060
• 负责人: MUKAI Kusuhiro
• 金额: $ 4.74万
• 依托单位: Kyushu Institute of Technology
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (B)
• 财政年份: 1989
• 资助国家: 日本
• 起止时间: 1989 至 1990
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-01470060/
• 关键词: Plasma arc heating; Iron; Effects of oxygen and sulfur; Surface tension; Marangoni flow; Molten pool geometry; プラズマ加熱; メタルプ-ル形状; 直接観察; 溶融鉄一酸素合金; 溶融鉄一硫黄合金; 表面張力の温度係数; 酸素濃度; 溶融鉄ー酸素合金

Experiments were conducted to clarify the melting and flow behaviors of Fe-O and Fe-0.5mass%C-S specimens heated with a plasma arc flame in a gas shielded chamber.The flow behaviors of the molten pool were observed by use of ZrO_2 particles as a marker. The observation indicated that the outward flow occurred at the surface of the molten pool for the case using the base metal with low oxygen concentration and the inward flow did for the high oxygen concentration.The temperature coefficient of surface tension (dgamma/dT) is negative for the lower oxygen concentration range than 0.007 mass%, but it is positive for the higher oxygen level.Flow behaviors of the molten pool can be regarded as a surface tension driven flow (Marangoni flow) from the relation between the temperature coefficient of surface tension and the oxygen concentration.The depth (D) of the molten pool increases and the width (W) decreases with the increase of the oxygen and sulfur concentration in the base metal.The linear relation were found between dgamma/dT and the ratio D/W of Fe-O and Fe-C-S specimens. Neither oxygen concentration nor sulfur concentration in the metal influences the shape of the plasma arc flame.Conclusively, it could be deduced that Marangoni flow was a dominant factor in determining the molten pool geometry.

采用等离子弧火焰在气体保护室中对Fe-O和Fe-0. 5 mass %C-S试样进行了熔化和流动行为的实验研究，并以ZrO_2颗粒为标志观察了熔池的流动行为。观察结果表明，对于低氧浓度的母材，熔池表面发生外向流动，而对于高氧浓度的母材，熔池表面发生内向流动（dgamma/dT）对于低于0.007质量%的氧浓度范围为负，熔池的流动行为可以看作是表面张力驱动的流动根据表面张力温度系数与氧浓度的关系，计算了Marangoni流动的温度系数。熔池深度（D）增加，熔池宽度（Fe-O和Fe-C-S试样的dgamma/dT与D/W比呈线性关系。金属中的氧浓度和硫浓度都不影响等离子弧火焰的形状，因此可以推断，Marangoni流是决定熔池几何形状的主要因素。

项目成果

瀧内 直祐: "溶鉄の表面張力およびアルミナとのぬれ性におよぼす酸素と温度の影響" 日本金属学会誌. 55. 180-185 (1991)

Naosuke Takiuchi：“氧气和温度对铁水表面张力和氧化铝润湿性的影响”，日本金属学会杂志 55. 180-185 (1991)。

向井 楠宏: "プラズマ加熱による固体鉄試料の溶け込み形状" 日本金属学会誌. 55. 36-43 (1991)

Kusuhiro Mukai：“等离子加热实心铁样品的焊接形状”日本金属学会杂志 55. 36-43 (1991)。

瀧内 直祐: "溶鉄の表面張力およびアルミナとのぬれ性におよぼす酸素の影響" 日本金属学会誌. 55. 44-49 (1991)

Naosuke Takiuchi：“氧对铁水表面张力和氧化铝润湿性的影响”日本金属学会杂志 55. 44-49 (1991)。