屏蔽金属电弧焊接（SMAW）解释了

我们屏蔽金属电lding is an electric arc welding process that joins metals together using a consumable electrode. It was first introduced in 1888 when Nikolay Gavrilovich Slavyanov used consumable electrodes as a tool to arc weld.

我们屏蔽金属电lding, commonly known as stick welding, remains to be one of the most commonly usedwelding techniquestoday. Stick welding is an immensely versatile welding process, as we can use it in almost any industry, environment, position and metal.

Let’s further dive into what differentiates stick welding from other welding processes.

What Is Stick Welding

屏蔽的金属电弧焊接（SMAW），也称为手动金属弧焊接（MMAW或MMA）是一种焊接过程，使用磁通涂层电极连接金属。

An arc forms when the electrode tip comes into contact with the workpiece. Fusion takes place as both the rod and workpiece melt, forming a weld pool from the molten metal.

Simultaneously,the flux coating of the electrodeis consumed, forming aprotective layer of shielding gas and slagin the weld area.

Slag deposits will eventually form in the weld bead as the metals cool down. The deposits in the weld metal can be chipped off using common shop tools.

这种手动金属弧焊接技术仅限于短焊缝，因为需要不断更换耗尽电极。

SMAW should not be confused with FCAW although they share some similarities. With both welding processes, the flux from the electrodes protects the molten weld metal from contamination. These processes do not necessarily need external shielding gases but there are differences in the electrode design and thus,flux-cored arc weldingis sometimes referred to as stick welding turned inside out

屏蔽金属电弧焊接工艺

在焊接之前，始终建议检查设备状况。对于安全性和焊接质量来说，具有功能齐全的电源，夹具，电缆和电极支架至关重要。

下一步是选择一个可以补充碱金属的电极。同时，必须在适当的设置中设置电源：直流电极负，直流电极正或交流电流。一根棒焊机中的一根电线连接到接地夹，另一根电线与电极支架相连。

To start the arc welding process, the base metal is struck with the electrode. A welding arc forms as the electrode melts in the weld pool.

Consuming the flux coating releases a shielding gas that protects the weld pool from atmospheric contamination. A constant arc length should be maintained as the covered electrodes slowly join the molten pool. Generally, the arc length should be approximately equal to the diameter of the core wire.

A layer of slag forms as the weld metal cools. It can be removed post-cleanup using a chipping hammer and a steel brush.

Electrodes

Electrode type is one of the determining factors in ensuring weld quality. Its chemical composition can influence the arc stability, deposition rate, depth of penetration and other factors. The electrodes come at a fixed length of 14″ (35cm) or 18″ (45cm) and the welder has to manually change them.

棒状电极分为三个主要类别：

• 纤维素电极have a high cellulosic proportion in their coating which is suitable for deep arc penetration and high weld speeds from its rapid burn rate. They can be used for any welding position, but the high levels of hydrogen have to be taken into account as it increases the risk of cold cracking in the热影响区（HAZ）。

• Rutile electrodes包含大量的氧化钛(金红石)the flux. This material helps promote lower spatter, a good bead profile and consistent arc operation. These electrodes can be used in almost any welding position and are usable in both AC and DC power sources. They also create a fluid and viscous slag that is easy to remove.

• 基本电极have high quantities of calcium chloride and calcium carbonate in their coating. They are used for welds that require good mechanical properties and resistance to cracking. Basic electrodes are suitable for high weld speeds since the slag freezes fast. This also comes in handy when welding in the vertical and overhead positions but in turn, the slag is harder to remove, and thus these electrodes are prone to create poor bead profiles.

另一方面，金属粉末电极具有磁粉涂层，以促进较高的焊接电流。与没有铁粉的电极相比，金属粉末电极具有更高的沉积速率和效率。

Power Source

Stick welding can be used in both alternating current (AC) and direct current (DC) power sources. The power source, whether DC negative, DC positive, or AC, should be set depending on the type of electrode.

The welding machine requires a constant current, which is determined by the electrode size. The voltage will depend on the arc length and rod composition and can be regulated by moving the electrode closer or farther from the workpiece.

材料

Stick welding is usually the best choice when welding thicker metals, while other methods such as TIG andMIG焊接are preferred for thin materials.

These are the materials that you can stick weld:

• Steel

• 不锈钢

• Chrome

• Nickel-based alloys

• 我ron

• Mild steel

• Aluminium

这种焊接技术不建议使用反应性材料，例如锆，塔塔勒姆，叶子和钛。这样做的主要原因是，屏蔽特性不足以防止污染。

Welding Machine

一个接地夹is needed to prevent electrical shock. It needs to be connected to the workpiece or fixture. The ground clamp must be capable of carrying the electric current without overheating to avoid hazards.

Welding cables在Smaw中使用的是灵活的和绝缘的。它们必须具有足够的横截面和长度，以降低电压下降的焊接电流。棍棒焊接机中有两根焊接电缆，一个用于电极支架，另一个用于接地夹。

An electrode holderdelivers the welding current to the electrode. It acts as a guide to precisely feed the electrode to the weld joint. Electrode holders vary in size and possess different current capacities.

Shielded Metal Arc Welding Variables

弧长是棒状焊接中最关键的因素之一。不同的电极材料和焊接应用将确定项目的最佳弧长。根据经验，弧长切勿超过芯线的直径。

Amperage受电极选择，焊接角和饰面的影响。Stick Welder手册和指南中有安培的建议。

旅行速度is influenced by the electrode angle and type. For example, a fast filling electrode may allow you to have a higher travel speed. Changing the travel speed incorrectly may leave a frail and shallow weld, since the deposits formed may be more or less than required.

焊接技术– Compared to other welding methods, the SMAW welder has more influence than the machine in determining the weld quality. Here are some of the patterns and techniques that are suited for different projects:

• Whipping the electrodeworks best on low-flux electrodes such as E6010, E6011 and E6013 that can be trapped in the weld. Whipping helps to burn and remove contaminates from the forward and back motion.

• 圆形技术is mostly used by beginners since it can create a consistent travel speed and works with most electrodes. Simply move forward slightly with each circular motion.

• Weaving通常在需要较宽的焊缝时使用。它是通过将电极一侧移到弧后通过将电极侧移动到一面来执行的。

Welding Positions –棒焊是最通用的焊接技术之一，可以以不同的角度进行，包括平坦，水平，垂直和头顶焊接位置。

Safety Requirements

在任何焊接项目中，都必须遵循安全程序。戴着合适的焊接头盔和手套，具有良好的通风和地面夹具的存在通常都是常识，但此外，不要忘记拥有适当的知识。

Remember that it’s easier to replace or repair a piece of equipment than to risk hazards such as a flash burn or bodily injury.

棍子焊接的优势

1. Stick welding can be performed in almost any environment.

2. 设备相当便宜且负担得起。

3. 容易在狭小空间使用。

4. 许多可用的电极可供选择。

5. 金属表面不必像在TIG welding

6. Can be used for a variety of metals and alloys, along with unique positions.

7. 便携式和轻巧的设备，无需随身携带汽油箱。

8. Gases produced are sufficient for protecting the weld metal.

Disadvantages of Stick Welding

1. Leavesspatter and slag deposits。

2. 产生有毒的烟雾。

3. 金属电极需要不断更换，电极存根浪费。

4. Difficult to weld thin materials.

5. 耗时，因为这是一个手动过程。

6. 需要技巧和培训以实现干净的焊缝。

7. Not suitable for reactive metals.

Applications of Stick Welding

Maintenance and Repair

Stick welding is versatile and highly mobile, which makes it perfect for quick repairs, even in harsh conditions. A stick welder can be used in windy conditions, rain and underwater, without compromising its weld quality. Stick welding’s unique trait is that it can weld unclean or rusty metals.

制造

Since shielded arc welding is fairly easy to learn and welding equipment is cheap, it is still one of the most popular methods in fabrication and construction. While some industries are shifting to more automated welding methods, many still prefer to use stick welding.

我mportant Points To Remember

我们屏蔽金属电lding is a versatile process that can weld a variety of metals. It is a relatively straightforward process to learn and it can produce high-quality welds.

尽管该技术是最古老的焊接形式之一，但创新继续提高其效率。

截至今天，棒状焊接仍然是那里最可靠的焊接方法之一，尤其是在经验丰富的个人进行的情况下。