# @stem_antics on Instagram

- **Type:** Video
- **Original URL:** https://www.instagram.com/p/Dd6tKgDA3ia
- **Gondola URL:** https://gondola.cc/posts/71131438-stem-antics-instagram
- **Thumbnail:** https://img.gondola.cc/tr:w-,h-,fo-auto/postThumbnails/89bcca3b21.jpg
- **Posted:** 2026-09-30T15:56:36.000+00:00
- **Account Owner:** Stem Antics (@stem_antics) — https://gondola.cc/stem_antics

## Caption

Open-die forging is how the largest steel parts on Earth are made, and it looks almost medieval until you see the scale.

Instead of pouring molten steel into a mold, a white-hot ingot is squeezed and reshaped between flat or simply shaped dies. The largest hydraulic presses deliver tens of thousands of tons of force, and forging manipulators, massive robotic arms, grip workpieces weighing hundreds of tons and rotate them between strikes.

Why go through all this instead of casting?

- Grain refinement: repeated deformation breaks up the coarse, dendritic structure left from solidification and recrystallizes it into finer, more uniform grains
- Closing internal voids: compressive forging welds shut shrinkage porosity and gas pockets from the ingot
- Grain flow: the metal’s fibers follow the part’s geometry, improving fatigue and impact resistance
- Directional strength: properties can be tailored along the load path of a shaft, roll, or beam

How the process works:

- Ingots are reheated to roughly 1100 to 1250 C, where austenitic steel is soft enough to deform without cracking
- The manipulator rotates the part between press strokes so the material is worked evenly from all sides
- Operators track “forging ratio,” the reduction in cross section, since more reduction generally means better consolidation of the core
- Surface cools faster than core, so parts return to the furnace repeatedly to avoid cracking

The manipulator is the unsung hero. It has to hold a glowing mass steady while absorbing shock from each stroke, then rotate it precisely for the next one. Coordination between press and manipulator is now heavily computer controlled.

These parts end up as ship propulsion shafts, turbine rotors, reactor pressure vessel components, and rolling mill rolls. Parts where failure is not an option.

#stemantics #metallurgy #materialsscience #manufacturing #engineering

## Stats

- **Views:** 19,136
- **Likes:** 160
- **Shares:** 0
- **Comments:** 3

## Tags

engineering, materialsscience, manufacturing, stemantics, metallurgy

---
Copyright (c) Gondola