Manufacturing Practices (BT-106) - Important Questions

Explain the principle, equipment, and working of oxy-acetylene (gas) welding. Describe the types of flames and their applications. Also discuss advantages and limitations of gas welding.

Compare the following welding processes in terms of heat source, consumables, typical applications, advantages and limitations: Shielded Metal Arc Welding (SMAW), Gas Metal Arc Welding (GMAW/MIG), and Gas Tungsten Arc Welding (GTAW/TIG).

Define welding heat input. Derive the expression for heat input per unit length for an arc welding process and calculate the heat input for a welding operation with arc voltage $V$, current $I$, welding speed $S$, and efficiency factor $\eta$.

List and explain the common welding defects in fusion welding (such as porosity, cracks, lack of fusion, slag inclusion, undercut). For each defect give possible causes and remedial measures.

Explain the classification of welding electrodes for SMAW. Discuss the role of electrode coatings and fluxes in arc welding and how they influence weld properties.

Draw and explain the conventional welding symbols used in engineering drawings. Describe the different types of welded joints (butt, fillet, lap, corner, edge) and typical applications of each.

Describe the principle, types, advantages, and limitations of resistance welding processes, such as spot welding and seam welding. What are the main process parameters affecting weld quality?

Explain the processes of brazing and soldering. Compare brazing, soldering and fusion welding in terms of temperature, joint strength, filler materials and typical applications.

Explain the principles, methods, advantages and limitations of common non-destructive testing (NDT) methods used for welded joints: visual inspection, dye penetrant testing, magnetic particle testing, ultrasonic testing and radiographic testing.

Discuss the significance of preheat, interpass temperature and post-weld heat treatment (PWHT) in welding high carbon steels and alloy steels. How do these practices influence weldability and residual stresses?

List the safety hazards associated with welding operations. Describe the protective measures and personal protective equipment (PPE) required to ensure safe welding practices, and explain the health effects of welding fumes.

Describe the basics of automated and robotic welding systems. Discuss the advantages, limitations, and typical industrial applications of automation in welding.