I Made Steel for Guan Yu: I Melted the Qinglong Sword at the Beginning

Traveling through time and becoming the son-in-law of Guan Yu, at the beginning, the sword is broken and the armor is broken. The entire army is out of food, and Xu Huang and Lu Meng attack from both sides. As a Baosteel engineer, I carry a hammer to improve the blast furnace, and I can cut through steel armor with one steel-making knife! Let's see how I use modern metallurgy to change the fate of the Martial Saint against the will of heaven!