JPS58107408A - Atmospheric gas supply amount control method - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

Detailed Description of the Invention The present invention provides #4 treatment of metals such as non-oxidation annealing, bright annealing, etc. using an atmospheric gas with a controlled composition.
A stone related to the method of controlling the amount of atmospheric gas supplied to the furnace body in ring melting.

When heat-treating metals, the main components of the gases used are oo, co, u, and o.

■Proverb, O,, N snow de ai, soon, COM ayan0
, is an oxidizing gas for most gold-14,
Oxidize or denucleate metals. tHl.

CO is a 1lje property, 'l is a neutral gas, so C
O and 00. , or Hl and H, Of) Whether the gas is oxidizing to a specific metal, 11-component, carburizing, carburizing, or de-scaling is determined by their partial pressure ratio (0010
01,t or ■Maro/Ha O).

(Note that this partial pressure ratio of 2k is also called the bound concentration from the degree of penetrating and de-enveloping of metals, and the condition of a partial pressure ratio with no yellow color is called the equilibrium concentration of carp.) ) By the way, atmospheric gases are generally classified into exothermic rare gases and endothermic gases according to the way they are generated. Zero exothermic gases generate heat because the fuel is completely or slightly incompletely combusted and the gas generation progresses due to the heat generated by the reaction. The combustion gas obtained by cooling the combustion gas and removing II and O is generally called DIX gas, and the one obtained by further removing OOl is called NX gas. In addition, endothermic gas is created by mixing hypohydrogen gas and air.
l! It is called an endothermic type because the summer response that takes part in its generation is achieved by external heating, and it is a reducing type that contains a large amount of co and n. It is also called ILX gas.

The atmospheric gas composition in the metal heat treatment furnace is adjusted by controlling the ratio of the supply amount of the exothermic gas per magnetic field time to the supply amount of the endothermic gas per magnetic field time. Figure 1 shows an example of this, in which a furnace body 1 is provided with an air supply pipe 1 for exothermic gas (NX gas) and an air supply pipe 3 for endothermic gas (RX gas). I numbered it in Analyzer 4 and its atmosphere I! Measuring the ratio of Co and Co in the gas, co7co, or (Co)
1100 is maintained at a predetermined value set in advance by the control device S, and controls the automatic control valve 6 provided in the air supply pipe 3. That is, in this case, exothermic gas is always supplied in a fixed amount through the supply pipe, and the supply ratio of the exhaust gas is controlled by controlling the amount of endothermic gas supplied relative to the amount of exothermic gas supplied. Met.

For this reason, if the time interval between loading and unloading the heated material into and out of the furnace body 1 is short and the door is opened and closed frequently, or when the gas seal part of the furnace body has deteriorated, both gases cannot be supplied as described above. If only the ratio was controlled, the critical amount of atmospheric gas would sometimes be insufficient.

In addition, to avoid such a risk, the supply amount of exothermic gas is set to a large amount, but in that case, the supply amount of endothermic gas also increases accordingly, resulting in wasteful consumption of atmospheric gas as a whole. A drawback arose.

The present invention has been made in view of the above-mentioned problems, and it is an object of the present invention to always economically realize appropriate heat treatment by eliminating excess or deficiency in the supply of atmosphere gas.

Next, the present invention will be explained in detail according to the following factors.

Note that the same reference numerals as in FIG. 1 in FIG.
An analyzer 7 that measures 11 degrees is installed, and the exothermic gas supply pipe is installed so that the measured concentration is within the permissible range preset in the control device I! The automatic control valve 1 is controlled.

In other words, if the concentration in the oven rises for some reason, the opening of the automatic see valve is increased to increase the amount of exothermic gas supplied in order to lower the concentration. Since the pressure ratio (Co100.) becomes smaller, it goes without saying that the opening degree of the automatic control valve 6 via the control device 5 also becomes larger. Furthermore, when the Os concentration decreases in the summer, the mass regulation mechanism is throttled and the supply amount of exothermic gas decreases, and the supply amount of endothermic gas also decreases accordingly.

This embodiment has the advantage that it can be modified to be a harmful bird by simply adding an additional device to the conventional device illustrated in FIG.

Further, in the above embodiment, the Os concentration in the atmospheric gas is measured, but the H and O concentrations may also be measured.

As explained in the embodiments above, the control method of the present invention measures the 01 concentration or H,0 concentration of the atmospheric gas in the furnace and controls the exothermic gas so that the value is always within the allowable range of the object to be heated. Since the total amount of gas supplied and the total amount of suction III gas is controlled separately from the supply ratio of gas, the amount of consumed gas is always maintained at the necessary and sufficient amount according to the operating status of the furnace, eliminating wasteful consumption as in the past. Or, there will be no shortage and it will be economical and effective.

[Brief Description of the Drawings] Fig. 1 is a system diagram showing the atmospheric gas supply system of a conventional atmospheric heat treatment furnace, and Fig. 1 is a system diagram showing the -jJ! FIG. 2 is a system diagram of an exemplary atmospheric gas supply system. l...furnace body! ...Exothermic gas supply pipe, l.
... Endothermic gas supply pipe, 4... Analyzer, explosion...
...control device, ...automatic double valve, 1 ...analyzer, I ...control device. ...Automatic w4 valve.

Claims (1)

[Claims] 1. Gas 00/OO, heavy or II in the atmosphere H9 in the furnace
s/H10 (hereinafter referred to as partial pressure ratio) is measured at 5IIR#, and the partial pressure ratio is always maintained at a predetermined value ζ and I
In an atmosphere heat treatment furnace in which the supply ratio of exothermic gas and endothermic gas supplied with I4 is controlled, the W inside the furnace is controlled.
I! The total supply amount of the exothermic latent gas and endothermic gas is controlled so that the 01 concentration or H, O concentration of the gas is always within the allowable mgPg of the heated object. Atmosphere 2I gas supply amount control building. 1 The gas partial pressure ratio is always maintained at a predetermined value in WB2 in the furnace, and the supply ratio of endothermic gas to exothermic gas that is supplied to the UL furnace is controlled. In a gas heat treatment furnace, we measure 0.6 degrees of atmospheric gas in the furnace, and the value is always 1111 permissible for the heated object! 2. The method for controlling the supply amount of atmosphere I215 gas according to claim 1, wherein the #1 amount of the exothermic gas is controlled so that the amount is within the range.