手工电弧焊过程微量硼过渡及其稳定性的研究

INVESTIGATION OF THE TRANSFER OF SMALL AMOUNTS OF BORON INTO DEPOSITED METAL DURING MMA WELDING

通过在焊条药皮中加入氧化硼或硼铁向焊缝渗入微量硼。研究了各种影响焊缝含硼量及其稳定性的因素,发现通过加入微量氧化硼渗硼,比加入硼铁渗硼更为稳定。并通过分析熔滴、熔池和熔敷金属中硼含量随时间的变化,研究了渗硼的动力学过程.发现通过加入氧化硼渗硼是氧化硼从熔滴形成开始不断还原,焊接金属硼含量不断上升的动力学控制过程;而通过硼铁渗硼是在最初形成熔滴时硼过量渗入,随后不断被氧化直至接近平衡的过程,熔敷金属中的硼含量受热力学平衡控制.

Small amounts of boron were transferred from the electrode to weld metal by adding boron oxide or ferroboron powder to the electrode covering. Various factors affecting this transfer and its stability were studied. It was found that the process of transferring boron into weld metal became more stable by adding boron oxide instead of ferroboron into the covering. The kinetic process of boronization was investigated by measuring the transient boron content in the droplet, molten pool, deposited metal. It was revealed that in the process of boronization by boron oxide, the content of boron was increased continuously by the reduction of the oxide from the beginning of the formation of droplet,and the boron content was controlled by the kinetic process. However, in the process of boronization by ferroboron, the content of boron was at first increased excessively to a high value in the droplet and then decreased by oxidation to a pseudo-equilibrium level in the molten pool, and the boron content was controlled by the thermodynamic factors.