What is the main disadvantage of electroslag welding process?

Disadvantages: Too high heat input to base. High temperature of welding needs cooling arrangement. Slow rate of cooling give columnar grain in weld.

How does electroslag welding work?

Electroslag welding works on the principle of joining two metals with heat generation between them due to arc and electric resistance. The arc is first created by applying a potential difference between the base and the electrode. This arc melts the filler and fills the cavity.

What is the limitation of electroslag welding?

Disadvantages of Electroslag welding: Coarse grain structure of the weld; Low toughness of the weld; Only vertical position is possible.

What is the difference between electroslag welding & Electrogas welding?

Electrogas welding is very similar in principle to electroslag welding in that it is used for welding thick section material in a single pass and in the vertical position. The main difference being that the heat for welding is generated by an arc which is formed between a flux-cored electrode and the molten weld pool.

What is reverse polarity in welding?

“Straight” and “reverse” polarity are common terms for “electrode-negative” and “electrode-positive” polarity. Welding currents with electrode-positive (reverse) polarity result in deeper penetration, while electrode-negative (straight) polarity has the benefit of faster melt-off and faster deposition rate.

Why carbon is used in carbon arc welding?

Why is carbon used in carbon arc welding? Explanation: Carbon is used in carbon arc welding, at the negative terminal of the cathode. The reason for employing carbon at the negative terminal is that, a lesser amount of heat is generated at the electron tip than at the workpiece.

What is the heating element in electroslag welding?

Electroslag welding (ESW) is a process that melts and joins metals by heating them with a pool of molten slag held between the metals and continuously feeding a filler wire electrode into it, as shown in Figure 1. The weld pool is covered with molten slag and moves upward as welding progresses.

What is ESW and EGW welding?

Electroslag welding (ESW) and electrogas welding (EGW) are two related procedures that are used to weld thick-section materials in the vertical or near-vertical position between retaining shoes.

What is Egw in welding?

Electrogas arc welding (EGW) is used for welding vertical butt joints of products such as ship shell plates, bridges, storage tanks, and pressure vessels.

What welding groove design is normally used for electroslag welding?

Weld Joint Design for Electroslag Welding: The main types of joints that can be welded by ESW process include butt, fillet, comer, transition, T-joint and the cross weld as shown in Fig. 11.13; however specially designed retaining shoes are needed for joints other than butt, corner and T-joints.

What are the three types of polarity?

There are three main types of polarity: direct current straight polarity, direct current reverse polarity and alternating current polarity.

Is DC positive or negative polarity?

In a direct current (DC) circuit, current flows in one direction only, and one pole is always negative and the other pole is always positive. In an alternating current (AC) circuit the two poles alternate between negative and positive and the direction of the current (electron flow) reverses periodically.