The temperature in forging was an accumulation process. The more heat released instantly, the stronger the furnace body's heat retention ability and temperature resistance. Thus, the temperature would also increase.
In modern industries, things such as converters, flat glass tempering furnaces, and open-hearth furnaces could achieve two to three thousand degrees.
The brick kiln that contained the cumulative wisdom of humans could also achieve a temperature of 800 to 900 degrees.
Even the iron smelting furnaces in some roadside workshops could control temperatures above 1000 degrees to melt pig iron.
Despite the territory being poor in many basic raw materials, it was not difficult to achieve a high temperature of 1500 degrees to melt the robot.
With the accumulated experience, they could use the calcium carbide method again.