Microstructure and Properties of 25MnV Steel by Zero-time Holding Quenching

The microstructure and mechanical properties of 25MnV steel by quenching with zero-time holding were studied,the martensite shape and transformation characteristics of the steel were analyzed.The experiment results show that,in the range of 830～910℃,the strength and hardness of 25MnV steel raise along with quenching temperature going up,the best strength and hardness can be obtained by quenching at 910℃.When quenching temperature is higher than 880℃,the properties of the steel by quenching for zero-time holding are better than those by tradition quenching.The microstructure of the steel is the finer lath martensite after zero time holding quenching,the reasons relate to the fined austenite crystalline grain and the non-uniform density of carbon in austenite.