Tempering curves (1 to 3 h) for EN 25CrMo4 steel (SAE 4130) after oil quenching (835-865 °C).
<a href="//commons.wikimedia.org/wiki/User:Cdang" title="User:Cdang">Cdang</a>, from provider data collected by C. Barlier, L. Girardin
<span class="int-own-work" lang="en">Own work</span>