| 0Cr18Ni10Ti stainless steel has good anti corrosion resistance and cold stamping performance, so it has been widely used in the manufacture of deep-drawing molding parts, acid pipeline and acid storage container etc.. But there are often some phenomenon such as excessive amounts of ferrite and uneven tissue components existed in the organization of the 0Cr18Ni10Ti stainless steel reducing its corrosion resistance. With the increasingly harsh application environment,0Cr18Ni10Ti stainless steel often occur corrosion failure in engineering application. Every year the economic loss caused by corrosion failure of the 0Cr18Ni10Ti stainless steel is huge. Therefore, the research has important engineering significance to improve the corrosion resistance of 0Cr18Ni10Ti stainless steel technology. At present, the mainly methods to improve the corrosion resistance of OCr18Ni10Ti stainless steel are heat treatment and surface modification, etc.. Among them, by heat treatment to improve 0Cr18Ni10Ti stainless steel corrosion resistance has features of simple process and equipment, low cost and time-consuming, so its application is more and more widely. But the traditional, single solid solution treatment or stabilizing treatment cannot effectively solve the tendency of 0Cr18Ni10Ti stainless steels to inter-granular corrosion and pitting tendency in the H+ and Cl- enrichment environment, at the same time, it is difficult to balance its hardness etc.. Therefore, discussing how to improve its corrosion resistance and ensure the better performance of hardness, etc., become one of the key technical problem in research. Researching on the heat treatment process technology of 0Cr18Ni10Ti stainless steel has important significance to its structure, resistance to corrosion, hardness and other properties.On the basis of literature research, this paper designed different process of solution treatment and solution+stabilization heat treatment to 0Cr18Ni10Ti stainless steel considering its processing equipment is simple, easy operation and low cost etc.. The solid solution treatment temperature and time and other process parameters of OCr18Ni10Ti stainless steel were optimized. The better system of solid solution treatment process of 0Cr18Ni10Ti stainless steel was obtained. The composite solution+stabilization heat treatment to 0Cr18Ni10Ti stainless steel samples was did on the basis of the solid solution. Then a better composite heat treatment process of solid solution+stabilization was obtained. And by metallographic analysis, weight loss method, SEM and hardness measurement, this paper discussed the effect of solid solution treatment and the composite solution+stabilization heat treatment on the microstructure, corrosion resistance and hardness of 0Cr18Ni10Ti stainless steels. The main conclusions in this paper are as follows:After 980 ℃,1040℃,1100℃ and 1160℃ solid solution treatment, the original organization of ferrite and carbide dissolved in great quantities, the group composition of OCrl8NilOTi stainless steels was more uniform, the corrosion resistance and hardness had vary degrees of increased. Among them, after 980℃×1.5h solid solution treatment, the weightlessness rate of OCrl8NilOTi stainless steels was reduced by 0.0231g/h to 0.0105g/h, the average hardness of 0Cr18Ni10Ti stainless steels was increased from 678.7HV to 853.6HV. After 1040℃×0.5h solid solution treatment, the weightlessness rate of 0Cr18Ni10Ti stainless steels was reduced by 0.0231g/h to 0.0104g/h, the average hardness of 0Cr18Ni10Ti stainless steels was increased from 705.4HV to 836.2HV. After 1100℃×1h solid solution treatment, the weightlessness rate of 0Cr18Ni10Ti stainless steels was reduced by 0.0231g/h to 0.0124g/h, the average hardness of 0Cr18Ni10Ti stainless steels was increased from 719.5HV to 747.1HV. After 1160℃×0.5h solid solution treatment, the weightlessness rate of 0Cr18Ni10Ti stainless steels was reduced by 0.0231g/h to 0.0127g/h, the average hardness of OCrl8NilOTi stainless steels was increased from 706.1HV to 902.1HV.The 890℃×2h composite solution+stabilization heat treatment to OCrl8NilOTi stainless steel samples was did on the basis of 1100℃×1h and 1160℃×0.5h solid solution, the original organization of ferrite and carbide were fully dissolved and the single austenitic organization was obtained, the tissue defects such as dendritic segregation was eliminated. Its grain size was uniform, grain boundary was clear and near no corrosion groove, corrosion resistance was improved significantly. Among them, after 1100℃×1h solid solution+890℃×2h stabilization treatment, the weightlessness rate of 0Cr18Ni10Ti stainless steels was reduced by 0.0231g/h to 0.0042g/h, the average hardness of OCrl8NilOTi stainless steels was increased from 719.5HV to 740.7HV. After 1160℃×0.5h solid solution+890℃×2h stabilization treatment, the weightlessness rate of 0Cr18Ni10Ti stainless steels was reduced by 0.0231g/h to 0.0074g/h, the average hardness of 0Cr18Ni10Ti stainless steels was reduced by 706.1HV to 679.4HV. But after 980℃×1.5h solid solution+890℃×2h stabilization treatment and 1040℃×0.5h solid solution+890℃×2h stabilization treatment, the hardness and corrosion resistance of 0Cr18Ni10Ti stainless steel materials were reduced compared with after single solid solution.The best heat treatment process for 0Cr18Ni10Ti stainless steel is 1100℃×11h solid solution+water cooling+890℃×2h stabilization treatment+air cooling. After such process the 0Cr18Ni10Ti stainless steel has good organization, hardness and corrosion resistance. This study has a certain value to improve the structure, hardness and corrosion resistance of 0Cr18Ni10Ti stainless steel. |
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