What happens to the (a) hardness, and (b) toughness of steel as the tempering temperature increases? Why do these changes occur? - Quora
![One Minute Mentor: Relation Between Tempering Temperature and Hardness - Shape Memory and Superelastic Technologies One Minute Mentor: Relation Between Tempering Temperature and Hardness - Shape Memory and Superelastic Technologies](https://www.asminternational.org/documents/10192/17082024/HTPro_011216_OMM_250.jpg/21beecba-ef31-40f0-bd33-5f56d1d330a7?t=1452270579042)
One Minute Mentor: Relation Between Tempering Temperature and Hardness - Shape Memory and Superelastic Technologies
![40 Carbon Steel Brinell Hardness vs. Tempering Temperature | Precision Machined Products Association 40 Carbon Steel Brinell Hardness vs. Tempering Temperature | Precision Machined Products Association](https://www.pmpa.org/wp-content/uploads/2010/10/40-carbon-hardness-temper-temperature.jpg?w=300)