What is STICK Welding? (SMAW)

Summary

Stick welding, also known as Shielded Metal Arc Welding (SMAW), is an electric arc welding process that uses a consumable electrode rod covered with flux. The process involves creating an arc between the electrode and the workpiece, which melts both the rod and the base metal. The flux releases gases that shield the weld, while a slag layer forms to protect the molten weld as it solidifies. The quality of the weld depends significantly on the operator's skill, and the choice of electrode must match the specific welding job.

Takeaways

• 🔌 Stick welding is an electric arc welding process that uses rod-shaped metal electrodes covered with flux material.
• 🔍 The American Welding Society calls this process Shielded Metal Arc Welding (SMAW), but it's also known as Manual Metal Arc Welding (MMA) or simply Arc Welding.
• ⚡ In stick welding, an electric current flows through the electrode, creating an arc between the electrode and the workpiece that melts both the electrode and the base metal.
• 🛠️ The metal from the electrode, called filler metal, mixes with the base metal to form the weld, making stick welding a consumable electrode process.
• 🌬️ The flux covering on the electrode releases protective gases that shield the weld, and the remaining covering melts into a slag layer that shapes and protects the weld as it solidifies.
• 🚫 The slag layer must be removed after the weld cools, as it protects but also covers the weld.
• 💡 Stick welding doesn’t require additional shielding equipment like high-pressure gas cylinders, making it simpler than other welding methods.
• 🔄 Stick welding machines usually have simple controls, with key welding variables depending heavily on the operator’s skill and technique.
• 🔋 Stick welding can be set up with either AC or DC current, with the polarity affecting the welding process.
• 🧪 Stick electrodes come in various compositions and must be selected based on the base metal, the joint position, and the required tensile strength.

Q & A

What is stick welding and what is it also known as?

Stick welding is an electric arc welding process that uses rod-shaped metal electrodes covered with a flux material. It is also known as shielded metal arc welding (SMAW) or manual metal arc welding (MMA).

How does the electric current function in stick welding?

In stick welding, an electric current flows through a metal electrode or stick. An arc forms between the end of the electrode and the workpiece, melting both the electrode and the workpiece metal to create a weld pool.

What roles do the base metal and filler metal play in stick welding?

The base metal is the metal in the workpiece, while the filler metal is the metal from the electrode that melts and becomes part of the welded structure. Stick welding always adds filler metal to the joint.

Why is stick welding considered a consumable electrode process?

Stick welding is considered a consumable electrode process because the electrode melts away during welding, becoming part of the weld.

How does the flux covering on the electrode contribute to the welding process?

The flux covering on the electrode releases protective gases when heated, which shield the weld and help stabilize the arc. The flux also melts to cover the weld pool with a protective slag layer, which shapes and protects the weld as it solidifies.

Why is there no need for additional shielding equipment in stick welding?

There is no need for additional shielding equipment, such as gas cylinders, because the gases generated by the flux covering fully protect the molten weld.

What are the primary controls on stick welding equipment, and how do they influence the process?

The primary controls on stick welding equipment are often just current and polarity. Many important variables in welding quality depend on how the operator positions and moves the electrode.

What are the different ways to connect direct current (DC) in stick welding?

Direct current (DC) in stick welding can be connected in two ways: DC electrode negative (DCEN) or straight polarity, where the electrode is negative and the workpiece is positive, and DC electrode positive (DCEP) or reverse polarity, where the electrode is positive and the workpiece is negative.

How should one choose the appropriate electrode for a stick welding job?

The appropriate electrode should be chosen based on its metal alloy composition, flux chemistry, and compatibility with the base metal and joint position. Electrodes often have an AWS classification code that provides this information.

What must be done to the slag layer after the weld has cooled?

The slag layer that forms over the weld pool during welding must be removed after the weld has cooled to ensure the quality and appearance of the weld.