Effects of Heat Treatment Processes on Mechanical Properties of 20MnVB Steel of Connecting Ring

In order to improve the strength and toughness of the connecting ring,20MnVB steel samples were heat treated in three different methods.The influences of heat treatment on the mechanical properties of 20MnVB steel have been analyesd and investigated.The results show that the microstructure of 20MnVB steel quenched at 820 ℃ and tempered at 280 ℃ is blocklike ferrite and tempered martensite,it's plasticity and toughness are a little higher than those of 20MnVB steel quenched at 880 ℃ and tempered at 280 ℃,while the both are almost same in tensile strength;the microstructure of 20MnVB steel quenched at 820 ℃ and tempered at 280 ℃ after prequenching at 950 ℃ are streaky ferrite and tempered martensite,it's tensile strength,plasticity and toughness are increased simultaneously.