slab reheating temperature is high.Thesolubility products of TiS andTi4C2S2 in austenite havebeenalso experimentally determined as follows:log [Ti] [S] = -3 2521T-2.01 log [Ti] [C]
Experimental ProceduresThe steels used are vacuum-meltedultra low-C steels, whosechemical compositions are listed in
It is well known that nickel is a beneficial alloying element in copper bearing steels as it prevents hot shortness. On the other hand, the addition of tin promotes hot shortness. T hough some mechanisms for promoting these phenomena have been suggested, a quantitative discussion has still failed to establish the cause. In the present study, changes in the composition in the vicinity of the scale/metal interface owing to high temperature oxidation were experimentally determined using pure irons with copper, nickel, and tin additions. T he experimental findings, such as the fraction of liquid phase and the change in composition in the progress of scale formation, were then explained by thermodynamic considerations using the Fe-Cu-Ni and Fe-Cu-Sn phase diagrams calculated from a computerised thermodynamic database. T he thermodynamic considerations were also applied to a quantitative discussion on hot shortness and some measures for preventing hot shortness of copper bearing steels were suggested.MST /4285
To predict solute carbon and nitrogen in Nb and Ti added extra-low carbon steels quantitatively, the phase stability of the carbonitride in austenite and/or ferrite has been calculated by using Thermo-Calc software to which some thermodynamicparameters were added for the Fe-Nb-Ti-C-N system.It has been confirmed that the (Nb,Ti)(C.N) phase has a miscibility gap island, which is predicted from the tieline sets between TiN-like temperature2,5,7,9) and grain growth3,9) in annealing after cold-rolling; hence, the precipitation behavior influences the mechanical properties such as elongation or drawability. Therefore, it is very important industrially to clarify the phase stability of the carbonitride in austenite (y) :NbC34 (1994) Fig. 3(a) differs from that in Fig. 3(b) Fig. 2appears in the y region. Figure 4 shows the effect of temperature on the three phases Fig. 6, a non-precipitated region lies near the each abscissa (it is as same as that in Fig. 3(b)). Whereas, though yv* is not indicated in Fig. 6(b
Facuity ofThe isothermal precipitation behavior of Nb(C,N) in austenite has been investigated using steels of different carbon contents, The observed progress of the precipitation in extra low carbon steel is much faster and size of the precipitates is apparently larger than those in steels with higher carbon content even though their supersaturations are the same. To explain this phenomenon,the local equilibrium at the austenite/ Nb(C.N) interface has been introduced into the classical nucleation theory and the sphericai growth theory, and a generalized precipitation modei has been proposed which can predict the precipitation behavior of extra iow carbon steels as well as that of HSLA steels. As a conclusion, this study clearly shows that the kinetics of MC-typeprecipitation is influenced not only by the precipitate-forming atomic product.Mx C, but also by its ratio, MIC.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.