| Q&P Process is the proposed in recent years, a new type of heat treatment process. Q&P steel is obtained with the Q&P process, it is a novel martensite steel with good com-binations of strength and toughness, the microstructure consists of martensite and retained austenite. Martensite as hard phase to provide steel strength, ritical residual austenite be-cause of the existence of its TRIP effect can effectively improve the strength of steel and plastic. In this paper, with reference to TRIP the composition design of the low carbon low alloy steel silicon manganese series 20Si2Mn steel, After vacuum induction furnace melt-ing, rolling in the laboratory preparation Q&P heat treatment used for the testing samples. Two step and step Q&P heat treatment tests have been carried out respectively, to study the related theory of Q&P steel and performance.The main conclusions are as follows:(1) Using both one-step and two-step Q&P heat treatment process of 20Si2Mn steel heat treatment; Compared to study the effect of different process on mechanical properties;(2) Q&P process is studied in different temperature of partition, the partition time, quenching temperature, two phase zone annealing temperature, the mechanical properties of the process parameters on the experiment of steel, the influence of the Q&P best heat treatment process parameters;(3) By SEM, TEM and XRD experiment method to test the steel had been used to characterize the microstructure of Q&P process is studied in different temperature distribu-tion, distribution of time, quenching temperature, two phase zone annealing temperature and the influence of the types of experimental steel microstructure, the change rule of mi-crostructure were studied;(4) The retained austenite in the Q&P steel qualitative and quantitative research. On the content of residual austenite content, distribution, morphology and stability were stud-ied. |
