Overload steam at three thousand pounds of pressure doesn’t push like wind. It cuts like an artillery barrage.
Fluid at seven hundred degrees Fahrenheit expands through a convergent-divergent nozzle into a lower-pressure casing. Then, its speed accelerates past Mach two. At two thousand feet per second, tiny droplets of condensed stone salt water hit metal with the striking force of lead shot.
Standard carbon steel blades, forged for agricultural water wheels or river tugs, would suffer severe bubbling blast pitting within twelve hours. Within forty-eight, outward-pulling creep would stretch the blade roots and throw hundreds of pounds of razor-sharp shrapnel through the cast-iron casing.
Giles stood on the raised gallery of the lower Bessemer foundry. He watched a fifty-ton metal bar of glowing alloy steel swing beneath the overhead frame crane.
Behind his eyes, the test model screen was calculating the exact metalworking recipe needed to withstand faster-than-sound steam creep.
“Twelve percent chromium,” Giles called down to Master Borin Bronze-Lung, who stood beside the heavy steam forging press with a long iron ladle.
“One point five percent molybdenum, zero point two percent carbon, and the remainder virgin iron ore from the high mines.
We need high creep rupture strength, pushback to sulfur pitting, and uniform grain structure after oil cooling.”
