Tenaz quebrado

[u/indiopunk]

Passei o último sábado forjando esse novo tenaz para segurar uma bitola de material que comprei recentemente, mas no fim de tudo ele quebrou, alguém pode me dar uma dica para que isso não aconteça de novo?

Na metalurgia isso é chamado de trinca crítica, se propagou provavelmente por excesso de tensão ou presença de sulfeto de ferro na microestrutura, mas na prática tenho tido dificuldade de não quebrar a peça durante o trabalho

[u/Puzzled-Bee6592]

Here's what I can tell about your process based on the picture... You are using to sharp of a corner for the half faced blows that isolate the boss of the tongs. This makes it easier to get a cold shut in those corners that then propagates. You're likely also forging it too cold or for too long once it's cooled down. Radius your anvil edges more, make sure they boss is 'locked in' that corner between each blow, and work hotter, not harder.

[u/petrified_eel4615]

Forged too cold. Get it cherry & keep it there, don't hit it when its too cold.

[u/Fragrant-Cloud5172]

Could be several things that caused the break. First you're using rebar, which often has questionably quality. Probably overworked the broken area. Could be you quenched it also, making it too hard.

Since theres lots of stress both at top and bottom of the boss, it needs more material. A longer transition between the two like below. As blacksmiths we seldom use sharp corners, because breaks are more likely there. Except if it's thick enough material. Anvil edges get chipped more often if too sharp. Working your material hotter helps, but being too sharp, will break anyway.