Do interstitial atoms such as hydrogen, carbon or nitrogen cause cracking, embrittlement and other problems?

Do interstitial atoms such as hydrogen, carbon or nitrogen cause cracking, embrittlement and other problems?

• A. False
• B. Not sure
• C. Sometimes
• D. True

Answer: (D)

Interstitial atoms in metals can disrupt the lattice and diffusion behavior enough to cause embrittlement and cracking under the right conditions. Hydrogen, in particular, diffuses rapidly and can accumulate at grain boundaries or tensile cracks, weakening bonds and promoting crack initiation and propagation—this is hydrogen embrittlement, a major concern in high‑strength steels and welds. Carbon and nitrogen, when present in significant amounts, can form carbides or nitrides and distort the lattice, raising strength but reducing ductility, and they can segregate to grain boundaries or interact with precipitates to promote embrittlement and cracking, especially under stress or at elevated temperatures. So, the statement is true: interstitial atoms can cause cracking, embrittlement, and related problems in metals under appropriate conditions.

Interstitial atoms in metals can disrupt the lattice and diffusion behavior enough to cause embrittlement and cracking under the right conditions. Hydrogen, in particular, diffuses rapidly and can accumulate at grain boundaries or tensile cracks, weakening bonds and promoting crack initiation and propagation—this is hydrogen embrittlement, a major concern in high‑strength steels and welds. Carbon and nitrogen, when present in significant amounts, can form carbides or nitrides and distort the lattice, raising strength but reducing ductility, and they can segregate to grain boundaries or interact with precipitates to promote embrittlement and cracking, especially under stress or at elevated temperatures. So, the statement is true: interstitial atoms can cause cracking, embrittlement, and related problems in metals under appropriate conditions.