In terms of the power of Allah, it is possible for the Prophet Dawud to cast iron into any shape he wished like wax, without heating and forging it. Elmalılı, the tafsir scholar, states the following regarding the issue:
"It seems that iron softens and dissolves so much in the fire that it becomes like ink used in writing. Then, who, among sane people, regards it as impossible for to divine power?
Some people reached the conclusion that what was meant by it was to say that he found and discovered melting iron by using fire and tools but
it is not true. The discovery and smelting of iron must have occurred before. However, applying sensitive technology to weave it like clothes by putting it in any shape like wax was an art granted to the Prophet Dawud. "
https://questionsonislam.com/question/who-invented-war-armorAllah knows best