martempering
/ˈmɑːtɛmp(ə)rɪŋ/Metallurgy
noun
A method of tempering steel that reduces its tendency to crack or distort, by rapid quenching to a temperature just above that at which martensite begins to form, allowing the temperature to equalize throughout (especially long enough for the isothermal transformation of austenite to martensite to begin), and then cooling slowly.
Origin
1940s. From mar- + tempering.