Which risk notably increased during the Han Dynasty, following the use of coke in iron smelting instead of charcoal?

💡 Explanation

The greater sulfur content in coke, relative to charcoal, led to increased sulfur content in the smelted iron; this increases the risk of arsenic embrittlement because arsenic segregates to grain boundaries alongside sulfur, therefore the iron becomes more brittle at high temperatures, rather than gaining strength.

• Which constraint increases when a Song Dynasty multi-bolt crossbow's cast bronze trigger mechanism becomes too massive?
• Which maintenance risk existed historically for bronze-tipped plows?
• Which hydrological effect was vital to continuously feed stepped wells ('baolis') constructed in arid regions of historic India?
• Which structural vulnerability emerges when a Roman fort wall section is built on unconsolidated reclaimed marshland?
• Which instability resulted if shipbuilding during the 18th century inadequately braced a warship's gunports?
• Which structural consequence increases when a Roman ballista launches projectiles beyond its design range?