| Because of its good oxidation resistance,corrosion resistance,creep resistance and excellent processing performance,310S heat resistant steel is often used as parts in high temperature,high pressure,corrosion and other media,such as the inner cover of high temperature annular annealing furnace.The same conditions,however,antioxidant 310S heat resistant steel production from abroad,corrosion resistance and service cycle are superior to domestic 310S heat resistant steel,so in this paper,domestic and foreign manufacturers to produce different 310S heat resistant steel as the research object(domestic for 1#,foreign production of 2#),with different manufacturer production 310S high temperature oxidation resistant properties of heat resistant steel for comparative study.The chemical compositions of domestic and foreign 310S heat-resistant steel hot rolled plates are similar,and the grain sizes are63.5?m and 31.8?m,respectively.In this paper,the weight gain method was used to test the oxidation kinetics curve of 310S heat-resistant steel.OM,XRD,SEM and SEM-EDS were used to characterize the chemical composition,microstructure,phase composition of the surface oxide film,oxide morphology,oxide film cross-section morphology and element distribution of 310S heat-resistant steel produced by different manufacturers.The evolution of oxidation kinetics curve of 310S heat resistant steel produced by different manufacturers and its influencing factors were studied.The formation mechanism of oxide film and the action mechanism of alloy composition and microstructure on 310S heat resistant steel produced by different manufacturers were studied.(1)The oxidation kinetics curves of 310S heat-resistant steel produced by different manufacturers conform to the parabolic rule at the oxidation temperature of800??1100?,which indicates that the oxidation process of alloy is controlled by element diffusion.The oxidation rate of 2#steel is lower than that of 1#steel at800?,900?and 1100?.When the oxidation temperature is 1000?,the oxidation rate of 1#steel is close to that of 2#steel,but the oxidation rate of 1#steel is slightly lower than that of 2#steel.Overall,the oxidation resistance of 2#steel is better.(2)Under the same oxidation temperature,the phase composition of oxide film generated on the surface of 1#steel and 2#steel is the same.The content of Fe oxide in the oxide of 1#steel is more,and the content ofCr oxide with better protection in the oxide of 2#steel is higher.When the oxidation temperature is 800?,the oxide films on the surface of 1#steel and 2#steel samples show a lamellar structure,in which the lamellar oxides of 2#steel are smaller in size and more closely arranged.When the oxidation temperature of 900?and above the sample surface oxide generated spinel structure,and with the increase of oxidation temperature,oxidation film peeling,oxide film structure is destroyed,the 1#steel oxidation membrane peeling is serious,the oxidation of 2#steel membrane spalling is relatively small,peeling off after the defects such as holes or cracks exist in the inner membrane.(3)At the oxidation temperature of 800?,thin monolayerCr2O3films were formed in the samples of 1#and 2#steel.When the oxidation temperature is 900??1100?,the thickness of the oxide film increases sharply,and the phenomenon of stratification appears.The inner layer isCr2O3film,and the outer layer is the solid solution formed by Fe3O4and spinel oxides(FeCr2O4,MnCr2O4,Mn3O4).There is no continuous distribution of Si O2layer at the interface between film and matrix of 1#steel.Internal oxidation occurs in the alloy,and the oxide film grows inuniformly towards the substrate boundary.The roughness of the oxide film interface is large and the bonding degree is weak.Continuous Si O2layer is formed at the interface between oxide film and matrix of 2#steel.The oxide film has uniform thickness and good adhesion. |
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