What blows up the star into a supernova is when it reaches the point of making iron. Also, only the stars with sufficient mass can turn into supernova, making iron and heavier elements require that much energy.

In my teens I worked in a steel foundry, putting together the composition to load and feed the furnaces. The oxygen furnaces burned for 10 - 12 hours to melt 80 tons each of recycled junk.

You cannot "learn" about this stuff unless you experience this in reality, hear the roaring of the gas and oxygen nozzles, and feel the heat of Hell (2000+ Celsius).

No fucking way can you melt H-beams of structural steel in the open ambient.