Under vacuum or vacuum argon blowing conditions,the influences of CaO-BaO-Al2O3-TiO2 and CaO-MgO-Al2O3-SiO2-CaF2 slags on denitrogenation from steel were investigated.

The result showed that: at the optional condi tions or:pH=8.5,aeration intensity is 180 m3/(m2·h), the removal rate of NH3- N was 55.6%after 24 h blowing, and the effluent NH3-N concentration could not limit biological treatment.

With slag splashing ratio of top-bottom combined blowing is 50 %, brick consumption is reduced by 0. 7 kg/t, gunning material consumption is reduced by 1. 22 kg/t.

Results show that the best results for molten bath stirring are achieved when six-nozzle oxygen lances are selected with included angle being ~17.5° , top blow rate ~30 000 m3/h, bottom blow rate 540 m3/h and the bottom blowing tuyeres being arranged at ~0.52 D and lance position ~1.7 m .

During LF refining,sulphur content in steel further decreases to 0.001%～0.002% by further added 800 kg synthetic slag,blown argon 600～900 L/min,after heating fed 600 m silicon-calcium wire then blown argon 30～45 L/min for 10 min with end slag basicity R = 4.5～5.5.

[N] was 0.040% and [O] was 0.0158% at end of VOD refining, and the analysis results indicated [N] 0.139% and [O] 0.0033% after nitrogen blown for 45 min in LF with blown nitrogen amount 50 m3with blown nitrogen average yield 33.07%.

In this paper, the behaviors of stainless steel in reduction period in 20 t STB combined blown converter is analysed. A formula is obtained: (%Cr)_s=4.483-7487/T-0.358lg[%Cr]-0.142 lg[%Si]-1.428lg V-0.038lg Q_(Ar).

The Φ5.0～22.0 mm wire coils of 0.35C high strength cold heading steel SCM435 with short-time annealing were produced at Ma'anshan Iron and Steel by hot metal pretreating-50 t top and bottom combined blown converter melting-65 t LF refining-6 strand 140 mm×140 mm billet concasting-SMS high speed wire coil mill control rolling and cooling process.

The spring steel 65Mn was produced by 100 t top and bottom combined blown converter melting - ladle furnace refining - 6 strand 150 mm×150 mm billet concasting.

Experimental study of boundary-layer control by blowing on a flat plate at M=2.5

Effect of blowing various gases into the boundary layer on the friction, heat, and mass transfer for a power-law variation of th

Formulas are derived which make it possible to determine the effect of various physical characteristics of the injected and external gases on the blowing coefficient for zero Mach number and a temperature factor of unity.

Considering that the blowing coefficients for heat transfer depend very weakly on the Mach number and the temperature ratio [1], it may be recommended that the formulas obtained for these values be used for other values of these parameters as well.

Blowing coefficient with arbitrary variation of the mass flow rate of the blown gas past a body around which flows a stream with

A note on the behavior of blow-up solutions for one-phase Stefan problems

It is proved that when the solution is blow-up in a finite time s(uo), and u0(x) is not a constant, then the free boundary will not be blow-up and the blow-up set is contained in the interval [0,l0).

Moreover, when f(u,t)=u1+μ for some μ>amp;gt;0, every blow-up point is isolated.

The blow-up property for a system of heat equations with nonlinear boundary conditions

This paper deals with the blow-up properties of solutions to the systems ut=Δu,vt=Δv in BRX(0,T) subject to nonlinear boundary conditions , in SRX(0,T).

Flow of a viscous fluid between a fixed disk and a blown rotating disk

Blowing coefficient with arbitrary variation of the mass flow rate of the blown gas past a body around which flows a stream with

The results are given of calculating the base pressure when hydrogen and argon are blown into the base region.

Tangential blowing of gas and surface cooling lead to elimination of the separated zone, for certain levels of blown gas flow rate and wall temperature.

Using a numerical method we investigate the effect of various factors (the Mach number of blowing, the type of blown gas, and the intensity of variation of the pressure gradient) on the stability of the boundary layer up to its separation.

A modified method bassd on the Terent'ev method of "active hydrogen" determination has been developed, by means of which both "active hydrogen" and CH3MgI addition can be determined.In this paper the procedure of the method was described in detail and a few examples of determination were given.In comparison with Kohler's method, though this method appears to be less satisfactory in accuracy, it has the advantage that the apparatus is simpler to construct and the determination easier and more rapid to be carried...

A modified method bassd on the Terent'ev method of "active hydrogen" determination has been developed, by means of which both "active hydrogen" and CH3MgI addition can be determined.In this paper the procedure of the method was described in detail and a few examples of determination were given.In comparison with Kohler's method, though this method appears to be less satisfactory in accuracy, it has the advantage that the apparatus is simpler to construct and the determination easier and more rapid to be carried out.

The Austausch coefficient may be obtained by wind structure. 1902 Ekman established the wind spiral theory in the friction layer. From the observed wind spiral, we may calculate of the Austausch coefficient by this theory. 1952 considered effect of the change of pressure field with height; i. e. the thermal wind effect, and found excellent results. But, Formula holds only for the condition in the stationary current flow, or in the stationary temperature pressure field and uniform temperature pressure gradient.In...

The Austausch coefficient may be obtained by wind structure. 1902 Ekman established the wind spiral theory in the friction layer. From the observed wind spiral, we may calculate of the Austausch coefficient by this theory. 1952 considered effect of the change of pressure field with height; i. e. the thermal wind effect, and found excellent results. But, Formula holds only for the condition in the stationary current flow, or in the stationary temperature pressure field and uniform temperature pressure gradient.In this paper, we consider the unstationary effect, as calculating the Austausch coefficient in the friction layer, and obtain a more general formula. Under some special constrains, it tends to be the or Ekman's formula. Then, this formula may be more accurate in calculation and more wide in application.Some calculations based on observed data by using these three different formulas are presented and compared.

Bath reactions during the oxidizing period of electric-furnace steelmaking withinjection were studied. It is found that,under favourable conditions,a rate of carbon removal ofabout 0.015—0.020%C per minute(that of the normal smelting with ore beingaround 0.005% C per minute only)may be obtained;(FeO)and[O]decreasesignificantly and approach to equilibrium with[C]during the oxidizing period,andthe decrement of[O]increases proportionately with the increase of the rate ofcarbon removal.Dephosphorization during the...

Bath reactions during the oxidizing period of electric-furnace steelmaking withinjection were studied. It is found that,under favourable conditions,a rate of carbon removal ofabout 0.015—0.020%C per minute(that of the normal smelting with ore beingaround 0.005% C per minute only)may be obtained;(FeO)and[O]decreasesignificantly and approach to equilibrium with[C]during the oxidizing period,andthe decrement of[O]increases proportionately with the increase of the rate ofcarbon removal.Dephosphorization during the oxidizing period is found to be rather ineffective,the average[P]removed amounts to about 0.004% only.With a supplementaryoperation of dephosphorization during the melting period,[P]can be reduced toless than 0.015% at the end of oxidizing period.However,the dephosphorizationmechanism in the case of the oxygen smelting is still not yet clear.