About: http://webisa.webdatacommons.org/65588524

Property	Value
http://www.w3.org/1999/02/22-rdf-syntax-ns#type	http://www.w3.org/ns/prov#Entity
http://www.w3.org/ns/prov#value	The heat treatment is preferably carried out for a time of about ??? to 2 hours while the treating atmosphere may be air or inert gas such as nitrogen or vacuum.
http://www.w3.org/ns/prov#wasQuotedFrom	google.com