Study On Strengthening And Toughening Process Of Maraging Stainless Steel

00Cr12Ni10MoTi is a low-temperature maraging stainless steel.It not only has high strength,but also has excellent toughness at low temperatures.It is becoming an important alternative steel for liquid oxygen,liquid nitrogen storage and low temperature components.Although it is developed from maraging steel,its strength-toughen mechanism is more complicated than the strength-toughen mechanism of maraging steel.In this paper,Ni and Ti,which have important influence on the strength and toughness of Maraging Stainless steel,are taken as the research objects,and their effects on the strength and toughness of 00Cr12Ni10MoTi steel are studied by various characterization methods and testing methods.The effects of solid solution and aging temperature on the structure and properties of the material are also studied,and the strengthening and toughening mechanism of maraging stainless steel is further discussed.It has practical application value for giving full play to the performance of the material.Firstly,the effects of Ni and Ti contents on the strength and toughness of00Cr12Ni10MoTi maraging stainless steel were studied.It is found that the increase of Ni content in the range of 9.27?10.1% improves the content of reversed austenite in the material and reduces the strength of the material,but also improves the toughness of the material,especially the low temperature toughness.When the Ti content is increased from 0.20% to 0.30%,the strength of the material is remarkably improved,and the precipitation of TiN inclusions and strengthening phase Ni₃Ti is also promoted,which impairs the toughness of the material.Secondly,after determining the composition of 00Cr12Ni10MoTi maraging aging stainless steel,the influence of solution heat treatment temperature on its strength and toughness was continuously studied.Studies have shown that when the solution temperature is 750?,the austenite grains and the martensite laths obtained after cooling are fine,and the volume fraction of the inverted austenite phase formed during aging is higher.With the increase of the temperature of solution heat treatment,the prior austenite grain boundary migrates,the grain and martensite lath begin to coarsen,the amount of reversed austenite formation decreases significantly,and the material strength increases slightly.The toughness of the material,especially the low temperature toughness,is significantly reduced.Finally,the changes of strength and toughness of 00Cr12Ni10MoTi maraging stainless steel at different aging heat treatment temperatures were studied.The study found that the increase in the aging temperature,the strength of the experimental steel gradually increased,and the toughness was significantly reduced.At aging at 400?,the low temperature impact energy reaches a minimum.When the aging temperature reached 500?,the strength of the experimental steel reached a peak with a large amount of rod-shaped Ni3Ti precipitated in the matrix.At the same time,a large amount of reversed austenite was formed,and the impact toughness of the experimental steel rebounded.The research results have important guiding significance for the actual industrial production of maraging stainless steel.