Influence of heat treatment on the yield strength of orthodontic stainless steel wires

Measurement of the magnetic moment in a cold worked 304 stainless steel using HTS SQUID

“…As a result of a phase transformation induced by a deformation, 304 SS has a certain amount of a (bcc) and e (hcp) martensite, which is a function of the temperature, alloy composition and plastic deformation [11]. Experimental results suggest that the martensite phase is responsible for the higher mechanical strength of these samples relative to undeformed samples [12].…”

The Influence of heat treatment in orthodontic arches made of stainless steel wire

“…The first treatment (3 min at 450 °C) is considered to be the best heat treatment for orthodontic applications because, according to Elias, de Biasi and Chevitarese 4 , the maximum yield strength of the material corresponds to the maximum FMR linewidth.…”

Influence of heat treatment on the mechanical properties of CrNi stainless steel orthodontic wires

“…Cold working can induce significant changes in the microstructure of the wire, which generally increase the strength and hardness of the material, but reduce the ductility and generate residual stresses 7 . To rearrange the atoms of the wire and break the residual stresses, heating is used 8 …”

“…However, the heat treatment of stainless steel orthodontic archwires is quite controversial in the literature, due to the different ranges of time and temperature used. 2 , 6 , 7 , 9 - 14 Supporters of heat treatment claim that the improvement in mechanical properties is due to stress relief, rather than a true transformation or precipitation of carbides. 6 , 11 Others believe that the improvement obtained is not enough to justify the procedure and that these changes are not clinically noticeable.…”