A METHOD FOR THE HEAT-TREATMENT OF HEAT-RECOVERABLE ARTICLES FORMED OF METALLIC COMPOSITIONS CAPABLE OF UNDERGOING A REVERSIBLE TRANSFORMATION BETWEEN AUSTENITIC AND MARTENSITIC PHASES TO EXPAND THE HYSTERESIS LOOP AND ARTICLE HEAT TREATED BY SUCH METHOD

摘要

pMfd. prod. showing thermal recovery is made of a metallic compsn. showing an enlarged martensite/austenite hysteresis loop. When the prod. is deformed, while it is the martensitic state, the deformation remains. On heating to a temp. at which the state is austenitic, the prod. tends to return to its undeformed state. The prod. has an elongation at break of at least 5%, and is stable during storage at 23 degrees C. The Ms temp. of the metallic compsn. is below ambient temp. The compsn. returns to its normal hysteresis loop when it is heated to a temp. above the As temp. of the enlarged hysteresis loop./p[FR2301604A1]