If a material has a melting temperature range instead of a melting point, then the dedicated Dutch word "smelttraject" applies. Similarly, "kooktraject" indicates a boiling temperature range instead of a boiling point. Usually these ranges apply to mixtures instead of pure substances. As linked above, these terms even have their own dedicated Wikipedia pages. However, have I never found explicit terms for these phenomena in English. Do they exist? The term "melting / boiling temperature range" can be used, but I am not sure if that is specific enough.
Likely example sentence (not sure because I am looking for the translation in the first place):
The boiling range of the liquid starts at 100°C and ends at 105°C.
(Meaning that the boiling starts at 100°C and ends at 105°C. The sentence does not have the intent to say that this mixture has a boiling point that lies somewhere between 100°C and 105°C. The context here is mainly chemistry.).
The translation does not exist in
translate.com did mention "melting range" and "cooking range", but I doubt if that is technically correct because usually the term "boiling" applies instead to liquid vaporization.