Question

The metal will be considered to have good weldability if,

1.  DBTT is above room temperature

 2. DBTT is at room temperature

3.  DBTT is much below the room temperature

4.  DBTT is above the recrystallization temperature

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Answer 1

The correct answer is (3) DBTT is much below the room temperature.

DBTT refers to Ductile brittle transition temperature, and is the temperature at which a material loses its ability to withstand any further force and fractures.

These materials perform well at room temperature but whenever temperatures are lowered, they become brittle and break.

Answer 2

Out of the options of DBTT being above room temperature, DBTT being at room temperature, DBTT being much below the room temperature and DBTT being above the recrystallization temperature, the metal will be considered to have good weldability if DBTT or Ductile brittle transition temperature is above the room temperature. The transition temperature and rate may vary from material to material.