Q1: Hydrogen in liquid steels is dissolved

ANS:A - as tiny gas bubbles.

Hydrogen in liquid steels is not typically dissolved as tiny gas bubbles. When hydrogen dissolves into molten steel, it does so in the atomic form, occupying interstitial sites within the crystal lattice of the steel matrix. However, hydrogen can form gas bubbles in steel under certain conditions, particularly during solidification or cooling of the steel. If the solubility of hydrogen decreases as the steel solidifies, the excess hydrogen may come out of solution and form gas bubbles within the solidifying steel. This phenomenon is known as hydrogen embrittlement and can lead to defects such as porosity in the steel. These gas bubbles can compromise the mechanical properties of the steel and reduce its structural integrity. Therefore, controlling hydrogen content and minimizing its presence in steel is important to prevent such issues.