JPS6364512B2 - - Google Patents

Description

[Detailed description of the invention]

This invention is intended to produce a rotor used for manufacturing glass fiber by discharging high-temperature molten glass from numerous micro-diameter orifices drilled in the side wall of the rotor using high-speed rotating centrifugal force. The patent application No. 56-197121 (Unexamined Japanese Patent Application No. 1982-1971), which was previously filed on December 8, 1981, relates to an alloy that has corrosion resistance and wear resistance against molten glass at high temperatures as a material for glass. Showa 58-
No. 100652) This is a further improvement of the alloy according to the invention. (For the structure and mounting mechanism of the rotor, see Japanese Patent Application Laid-Open No. 57-106532 or U.S. Patent No.
Please refer to No. 4392878. ) As stated in the above-mentioned specification,
The bottomed cylindrical rotor used to manufacture glass fiber by the rotary centrifugal force method is heated to a high temperature in the atmosphere and operates at approximately 2000 rpm.
Because the molten glass rotates at such a high speed, and the molten glass passes at high speed through numerous micro-diameter orifices drilled in the side wall, the following requirements are required of the alloy material that forms the rotor. . 1. Must have high-temperature mechanical strength that can withstand centrifugal force generated by high-speed rotation. 2. Must have sufficient abrasion resistance against abrasion caused by the passage of molten glass through the orifice at high speed. 3. Must have sufficient oxidation resistance against air at high temperatures. 4. Must have sufficient corrosion resistance (alkali resistance) against molten glass. 5. The oxide film inevitably formed on the surface of the alloy has excellent corrosion resistance against molten glass. Conventionally, as an alloy that can be used as a material for rotors,
Ni containing one or two of Co and W
-Cr alloys (e.g., U.S. Pat. No. 3010201;
3318694, 3806338), Co-Cr alloy containing one or both of W and Ni (see, for example, US Pat. No. 3933484), or Fe-Ni
- Cr-based stainless steel alloys (for example, SUS310) are known. However, among these alloys, SUS310
As shown later in the comparative data of Examples, the life of the rotor is so short that it is hardly of practical use. In addition, the above-mentioned Ni-Cr alloy containing Co and W, and the Ni-Cr alloy containing W and Ni.
Of the various characteristics that the alloy should have, Co--Cr alloys have the following properties, especially for the purpose of increasing high-temperature mechanical strength:
Since large amounts of expensive Co and W are contained, not only does the production cost of the alloy increase, but the corrosion resistance of both the alloy itself and the oxide film that inevitably forms on the surface of the alloy deteriorates, resulting in damage to the molten glass. The problem is that the durability of the rotor cannot be significantly improved. The purpose of the invention of JP-A No. 58-100652 mentioned above is to avoid using expensive Co as an alloy component, and to provide a material that can withstand harsh usage conditions such as rotating at high speed while contacting molten glass at high temperatures. However, the object of the present invention was to provide an alloy material with which a rotor with significantly superior durability (life) than conventional rotors could be formed at a low cost. The above purpose is to contain 0.05 to 0.50% C by weight,
15 to 35% Cr, 1 to 7% W, 0.10 to 0.25% Ti, 0.10 to 0.25% Zr, approximately 1
By manufacturing a cylindrical rotor for discharging molten glass fiber using an alloy consisting of %Nb, the balance Ni (however, the Ni content is over 55%), and unavoidable mixed impurities. achieved.
(See Examples.) If necessary, up to 2.0% of Si or Mn, or both, could be added to this alloy as a general deoxidizing agent. An object of the present invention is to further improve the alloy of the invention of JP-A-58-100652 mentioned above to obtain an alloy which can further significantly extend the life of the rotor. This object was achieved by adding 0.05 to 0.20% by weight of nitrogen (N) to the composition of the alloy in the above-mentioned invention. That is, the high-temperature corrosion-resistant and wear-resistant alloy used as the manufacturing material for the cylindrical rotor for discharging molten glass fiber of the present invention contains 0.05 to 0.50% C and 15 to 35% by weight.
Cr, 1 to 7% W, 0.10 to 0.25%
Ti, 0.10 to 0.25% Zr, 0.9 to 1.1%
Nb, 0.05 to 0.20% N, greater than 0%;
The composition consists of 2.0% or less of Si and/or Mn, the balance being Ni (however, the Ni content is 55% or more), and unavoidable impurities. Next, the limitation of the range of each component in the alloy of the present invention will be explained, partially overlapping the description in the specification of Japanese Patent No. 58-100652 and the drawings. C is dissolved in the base metal or forms carbides such as Cr and W, and contributes to increasing the mechanical strength and wear resistance of the alloy at high temperatures. However, if the C content is too high, the machinability of the alloy deteriorates, making it difficult to drill an orifice with a minute diameter through which molten glass is discharged. Also, generally C
If the content is too high, carbides such as Cr and W are formed excessively, reducing the content of metal Cr in the base metal, and the homogeneity of the structure is lost, resulting in a decrease in corrosion resistance against molten glass. . The influence of C content on the high-temperature mechanical strength and corrosion resistance against molten glass of the alloy of the present invention is illustrated in the curve diagram of FIG. Curve B is temperature
Curve C is the tensile strength at 1100℃, and the temperature is 1140℃.
shows the percent corrosion loss due to molten glass after 240 hours. According to this curve diagram, the C content is between 0.4 and
Although the corrosion resistance deteriorates slightly at 0.5%, the loss due to corrosion is only a small amount of about 4%, and at this level there is no practical problem. Therefore, judging from FIG. 1, the permissible range of C content in the alloy of the present invention was determined to be a lower limit of 0.05% and an upper limit of 0.50% in consideration of machinability and alkali resistance. Si is added to adjust the oxygen removal of the alloy, but if too much Si is added, the toughness of the alloy decreases, and the corrosion resistance of the alloy itself and the oxide film that inevitably forms on the surface of the alloy against molten glass deteriorates. . Therefore, the upper limit of the Si content was set at 2.0%.
Regarding the lower limit, there is no particular restriction other than that it be greater than 0%. Mn is also added to adjust the oxygen removal of the alloy. If this amount is too large, the oxidation resistance of the alloy at high temperatures will deteriorate, so the upper limit of its content was set at 2.0%.
Similarly to the above, there is no particular restriction on the lower limit other than the lower limit being greater than 0%. Cr is a necessary element for improving wear resistance and oxidation resistance by forming a solid solution in the base metal or by combining with C to form a carbide. The rotor for discharging glass fibers itself is heated to a high temperature of over 1000℃. In this case, in order to prevent the rotor life from decreasing due to scale precipitation, the Cr content should be set to 15
% is required. However, if this amount is too large, acidic oxide Cr ₂ O ₃ will be generated on the alloy surface, and Cr
By containing a large amount of Ni, the Ni content inevitably decreases, and the corrosion resistance against alkaline molten glass deteriorates. In this connection, the upper limit of Cr content was set at 35%. The Ni content must be 55% or more to ensure the alkali resistance of the alloy. W forms a solid solution in the base metal or combines with C to form a carbide, thereby increasing the high-temperature mechanical strength and wear resistance of the alloy. However, if it is too large, the corrosion resistance to molten glass and the oxidation resistance at high temperatures are significantly reduced. The influence of the W content on the high-temperature mechanical strength and corrosion resistance against molten glass of the alloy of the present invention is as illustrated in the curve diagram of FIG.
is the tensile strength at a temperature of 1000℃, and curve E is the temperature
Curve F shows the tensile strength at 1100°C at a temperature of 1140°C.
shows the percent corrosion loss due to molten glass after 240 hours. According to this curve diagram, it can be seen that the addition of a large amount of W significantly reduces the corrosion resistance of molten glass. However, as mentioned in the section on component limitation of C, there is no problem in practical use up to 4% corrosion loss, that is, up to 7% W content. Therefore, the permissible range of W content is 1 from the viewpoint of Figure 2.
7%. Ti, Zr, and Nb combine with C to form granular carbides, and these carbides have the property of being difficult to form a solid solution in the base metal even at high temperatures, which increases the mechanical strength and resistance of the alloy at high temperatures. Improves wear resistance,
It is also an effective element for preventing C from combining with Cr to form carbides in the form of a chain network, thereby improving the toughness of the alloy. However, if there are too many of these, the work will be complicated when melting the alloy, and although the cost will be high, the effect of addition will not increase.As a result of experiments, the optimal ratio is 0.10 to 0.25%.
of Ti, 0.10 to 0.25% Zr, and 0.9 to 0.9%
It was set at 1.1% Nb. It was found that N contributes to increasing the mechanical strength and wear resistance of the alloy at high temperatures by forming a solid solution in the base metal or forming nitrides with Ti, Zr, and Nb. However, if the N content is too high, Ti, Zr,
Excessive formation of Nb nitride inhibits the carbide spheroidizing effect of Ti, Zr, and Nb, making the alloy brittle. Furthermore, the N
The solubility of N is 0.23%, and the solubility of N further decreases as the temperature decreases to the freezing point.
If N exceeds 0.20%, many pinholes due to nitrogen gas will occur in the casting of the alloy of the present invention, making it difficult to put it to practical use. The influence of the N content on the high-temperature mechanical strength and corrosion resistance against molten glass of the alloy of the present invention is as illustrated in the curve diagram of FIG.
is the tensile strength at a temperature of 1000℃, and curve H is the temperature
Curve I shows the tensile strength at 1100°C at a temperature of 1140°C.
shows the percent corrosion loss due to molten glass after 240 hours. According to this curve diagram, it can be seen that the high temperature mechanical strength and corrosion resistance are gradually improved as the N content increases. Therefore, the lower limit of the allowable range of N content of the alloy of the present invention can be determined from Fig. 3.
0.05%, and the upper limit was set at 0.20% from the viewpoint of pinhole generation due to nitrogen gas and inhibition of carbide spheroidization of Ti, Zr, and Nb. There are two methods for adding N to an alloy: stirring the molten alloy in a nitrogen gas stream at a temperature of 1,600 ℃ and absorbing nitrogen gas into the molten alloy for a certain period of time; There are ways to add nitrides to alloy compositions. However, since homogeneous absorption is difficult in the former case,
The latter is a better option. Ni is a basic element of the alloy of the present invention. This is because rotors for discharging glass fibers are used extensively at high temperatures of 1000°C or higher. If Fe is used as the basic element, the high-temperature mechanical strength of the alloy and corrosion resistance against molten glass will be insufficient, and if Co is used as the basic element, the corrosion resistance against molten glass will be insufficient. However, it is inappropriate because it increases the cost. Therefore, the remaining content after excluding the above-mentioned component elements necessary for forming the alloy of the present invention and the unavoidably mixed trace impurity elements was determined to be Ni. However, as mentioned above, in order to ensure corrosion resistance against alkaline molten glass, the Ni content was increased to 55%.
% or more. Impurity elements that are unavoidably mixed include Fe,
There are P, S, Cu, etc. In particular, Fe may be contained up to 5.5%. Examples and Comparative Examples Table 1 shows the compositions of four examples of the alloy according to the present invention. Table 1 also lists the compositions of a number of comparative examples. In order to contain nitrogen in the alloy of this example, commercially available ferrochrome nitride (component: N6.35
%, Cr58.8%, remaining Fe. ) was added in the calculated amount. Using each alloy with the composition shown in Table 1 as a material, (1) high-temperature tensile test piece according to JIS-G-0567, (2) corrosion test of 5 mm thickness, 15 mm width, and 50 mm length. (3) A cylindrical rotating body with a bottom made of cast metal with an outer diameter of 300 mm, a height of 50 mm, and a peripheral wall thickness of 3 mm was manufactured, and several thousand orifices were drilled in the side wall to discharge the molten glass fiber. It was used as a rotor for High temperature tensile tests were carried out at temperatures of 1000°C and 1100°C and a strain rate of 5% elongation per minute. Corrosion tests were conducted by immersing test pieces in molten glass at a temperature of 1140°C for 240 hours and measuring the percent weight loss. In the practical glass fiber discharge test, the average temperature on the outside of the circumferential wall of the rotor was maintained at approximately 1010℃, the rotor was rotated at a rotation speed of 2500 to 2100 rpm, and molten glass was discharged from the nozzle to form fibers. The durability of the rotor, that is, the average number of hours of service life, was measured. The results of the various characteristic tests described above for each of the example alloys in Table 1 are shown in Table 2. Second
In the table, various characteristic values of the comparative example alloys shown in Table 1 are listed together with data cited from the specification of Japanese Patent Application No. 1971/1983 and the specifications of various US patents. As can be seen from the average lifespan column in Table 2,
-The life of the rotor made using the alloy according to the invention of No. 100652 is about 300 to 350 hours, whereas the life of the rotor made using the alloy according to the present invention is significantly improved to 450 to 600 hours. You can see that.

【table】

【table】 [Brief explanation of drawings]

FIG. 1 is a curve diagram showing the influence of C content on the high-temperature tensile strength and corrosion resistance against molten glass of the alloy of the present invention. FIG. 2 is a curve diagram showing the influence of W content on the high-temperature tensile strength and corrosion resistance against molten glass of the alloy of the present invention. Figure 3 shows the effect of N on the high temperature tensile strength and corrosion resistance to molten glass of the alloy of the present invention.
A curve diagram showing the influence of content.

Claims (1)

[Claims] 1 0.05 to 0.50% C by weight, 15 to 35%
Cr, 1 to 7% W, 0.10 to 0.25%
Ti, 0.10 to 0.25% Zr, 0.9 to 1.1%
Nb, 0.05 to 0.20% N, greater than 0%;
High-temperature corrosion resistance as a manufacturing material for cylindrical rotors for discharging molten glass fibers, consisting of 2.0% or less Si and/or Mn, the balance Ni (however, the Ni content is 55% or more), and unavoidable mixed impurities. Wear-resistant alloy.