碳电弧焊接 - 优势和缺点
什么是碳电弧焊接过程：
- 碳电弧焊接是当今仍在使用的最古老的焊接技术之一。
- 碳电弧焊接的过程使用低电压，高AMP的电能在碳电极之间形成弧线和焊接的材料之间，以加热金属。如果在两个技术被称为双碳电弧的两个碳电极之间形成弧。
- 单碳弧焊使用的技术direct current power supply which if required, filler rod may be used in Carbon Arc Welding. End of the rod is held in the arc zone. The molten rod material is supplied to the weld pool.
- 盾牌（中性气体，通量）可用于焊接池保护，具体取决于焊接金属类型。使用笔直的极性连接。
Principle and Working Of Carbon Arc Welding
In carbon arc welding, the arc heat between the carbon electrode and the work melts the base metal and, when required, also melts the filler rod. As the molten metal solidifies, a weld is produced. The non-consumable graphite electrode erodes rapidly and, in disintegrating, produces a shielding atmosphere of carbon monoxide and carbon dioxide gas. These gases partially displace air from the arc atmosphere and prohibit the oxygen and nitrogen from coming in contact with molten metal. Filler metal, when used, is of the same composition as the base metal. Bronze filler metal can be used for brazing and braze welding.
工件必须没有油脂，油，秤，油漆和其他异物。这两块应紧紧地夹在一起，没有根开口。他们可能会被焊接在一起。
碳电极1/8至5/16英寸（3.2至7.9毫米）的直径可使用，具体取决于焊接所需的电流。电极的末端应用长锥度到一个点制备。该点的直径应约为电极的一半。对于钢，电极应从电极支架突出约4.0至5.0英寸（101.6至127.0毫米）。
可以通过使电极的尖端与工作接触并立即将其提取到正确的焊接长度来击中碳弧。通常，最好在1/4至3/8英寸（6.4和9.5毫米）之间的弧长。如果弧长太短，则可能会导致熔融金属过多，从而产生脆性焊缝。
当弧因任何原因破裂时，不应直接在热焊接金属上重新启动。这可能会在接触点上引起焊缝的硬斑。应以冷金属启动弧线，直至关节的一侧，然后迅速返回到要恢复焊接的点。
When the joint requires filler metal, the welding rod is fed into the molten weld pool with one hand while the arc is manipulated with the other. The arc is directed on the surface of the work and gradually moved along the joint, constantly maintaining a molten pool into which the welding rod is added in the same manner as in gas tungsten arc welding. Progress along the weld joint and the addition of a welding rod must be timed to provide the size and shape of weld bead desired. Welding vertically or overhead with the carbon arc is difficult because carbon arc welding is essentially a puddling process. The weld joint should be backed up, especially in the case of thin sheets, to support the molten weld pools and prevent excessive melt-thru.
对于14至18号钢板中的外角焊缝，碳弧可用于无需填充金属将两张纸焊接在一起。这种焊缝通常比在类似条件下制造的屏蔽金属弧形焊缝更窒息，更经济。
优点：
- 设备和焊接操作的低成本；
- 不需要高水平的操作员技能；
- 该过程很容易自动化；
- Low distortion of work piece.
缺点：
- 焊缝的不稳定质量（孔隙率）；
- 电极的碳污染焊接材料用碳化物。
