One thing not mentioned, is that solder alloys have different melting temperatures. Some alloys, i.e. 50/50 and 60/40 are in the 183 to 212C range, while some may need as much as 300C to melt. Silver solder can need 450C or higher to melt. So depending on the original alloy, the melting temp may be lower or higher.
https://www.petervis.com/Education/S...elting%20point.