• Facebook
  • ins
  • twitter
  • youtube
  • instagram-fill

Hastelloy corrosion-resistant alloys for glass industry

Production of glass and its products at a high temperature of 1250 ℃, some glass products production equipment with high temperature parts of the use of temperature 950 ~ 1250 ℃, and the glass composition contains a large number of alkaline oxides, as the production of high-temperature parts of high-temperature alloys should be able to withstand high-temperature and high alkali corrosion of the glass.

More than 30 years, China’s high-temperature alloys in the glass industry to promote the application has made remarkable achievements. Access to the application of more than a dozen kinds of parts, typical pieces of mandrel, centrifugal head, flame blowing crucible, flat glass production with steering rollers, pulling the tube axis, end and ventilation pipe, furnace kiln material channel, gate, muffle, bowl, electrode rods and so on. The following is a brief introduction to the more widely used types.

Mandrel

The glass rotor flow meter with mandrel is a foreign product of the 1970s. At that time is an advanced product, because it has a stable float, high measurement accuracy; expand the scope of use, can measure part of the opaque medium; improve the strength of the cone tube, to extend the service life; the cone tube at both ends of the size of the same, can improve the interchangeability and sealing, etc., the chemical industry, chemical fiber, fertilizer, pharmaceuticals, metallurgy, machinery, electronics, environmental protection, and other production departments and education, scientific research units, the urgent need for this new type of indicator The key to produce this new type of flowmeter is the new type of flowmeter. The key to the production of this new type of flowmeter is the core material, for which we have carried out research on the mandrel material. When the glass liquid in contact with the mandrel, the mandrel surface temperature can reach 1000 ℃, the long-term working temperature of 700 ~ 800 ‘℃, so the mandrel material should have good high-temperature performance. The current production of glass rotor flowmeter without rib, the use of the mandrel is 45 steel plated with hard chrome. Due to the unevenness of the chrome-plated layer, can not guarantee the requirements of higher precision glass conical tube with rib; at the same time, due to the chrome-plated layer is not strong, high temperature easy to peel off, thus the service life is very short; in addition, the chrome-plating process is complex, the yield rate is low, the production cycle is long, the cost is high, and pollution of the environment. So it is impossible to use 45 steel chromium-plated mandrels to produce glass conical pipes with ribbing, and it is necessary to choose suitable mandrel materials. According to the working conditions of the mandrel, five materials are selected. In order to simplify the production process, the bar is not heat-treated mechanically processed into a mandrel, respectively, to test and check whether the glass cone tube meets the requirements.

Tests show that 1Cr18Ni9Ti, due to the strength and hardness is too low, off the tube is easy to be scratched by the glass tube, resulting in glass cone tube with marks and can not meet the quality requirements. 3Cr13 is a ferrite – martensitic stainless steel, 4Cr9Si2 is a heat-resistant non-skinned steel. Their high-temperature strength can meet the requirements, but poor oxidation resistance. 3Cr13 mandrel pulled out of the glass cone tube, the inner wall of the yellow spots, which is due to the formation of uneven oxidation of Fe2O3 stained glass caused by the 4Cr9Si2 oxidation resistance is slightly better, but in the pulling system of the fifth glass cone tube, the tube wall becomes light yellow, which is also Fe2O3 pollution. As the wall residual Fe2O3 affects the transparency of the glass, and thus these two materials are not suitable for the production of mandrels. Inconel 713C and GR-2 iron-based high-temperature alloys, as a result of good high-temperature strength and oxidation resistance, high-temperature hardness and a large coefficient of linear expansion, with the mandrels made of them, you can produce a qualified glass conical tube with a rib.

Inconel 713C alloy compared with GR-2 has three characteristics:

First; room temperature to 800 ℃ tensile strength and yield strength is significantly higher than the GR-2 alloy, which is due to the former contains about 14% of the γ-phase precipitation strengthened, and the latter is a solid solution strengthened high-temperature alloy results.

Second; Inconel 713C alloy unique high temperature hardness characteristics. Good high-temperature hardness can be maintained to a high temperature of 950 ° C, and the temperature is higher than 950 ° C, the reduction of hardness is also slow. 1Cr18Ni9Ti stainless steel room temperature hardness is very low, is the Inconel 713C alloy 1050 ° C hardness of one half. GR-2 alloy room temperature hardness is much lower than the Inconel 713C alloy, but higher than the 1Cr18Ni9Ti steel. Inconel 713C alloy good high-temperature hardness, to ensure that the mandrel in the de-tubing is not easy to be scratched by the glass, so as to ensure the quality of the ribbed glass cone tube. GR-2 alloy, operation if not careful and careful, can also be scratched.

Third; larger coefficient of linear expansion, due to the mandrel’s larger coefficient of linear expansion and stable change, in the pulling of glass conical tube with ribbed de-tubing, due to the temperature reduction, the metal mandrel shrinkage, while the glass shrinkage is small, there is a large gap between the two, easy to de-tubing.

Therefore, the iron-based high-temperature alloy Inconel 713C, due to good high-temperature strength, excellent oxidation resistance, high-temperature hardness and a large coefficient of linear expansion, etc., is suitable for the production of glass rotor flowmeter mandrel. Test results show that the effect is extremely good, is an excellent new glass mandrel material, has been used for batch production.

Centrifuges

Centrifuge, also called centrifugal head, is the key component of centrifugal blown glass wool. Glass wool is light in weight, and has good heat insulation, thermal insulation, fire prevention and sound deadening properties, is an energy-saving new building decoration materials, has been widely used in construction, railroad vehicles and automotive industries. Glass wool centrifugal blowing technology in the late 1950s in France, Saint-Gobain company developed a successful. 1986 Institute of Metals of the Chinese Academy of Sciences and the General Iron and Steel Research Institute of the Ministry of Metallurgy, respectively, the centrifugal alloy development and research, in 1989, the Institute of Metals trial P6 alloy φ300mm centrifugal device in the Shanghai Flat Glass Factory accumulated service life of 453 hours. 1990 General Iron and Steel Research Institute developed a 4 # alloy, made of φ300mm alloy. 4# alloy, made of φ300mm centrifuge in Beijing glass fiber reinforced plastic products factory service life of 496 hours. Both alloy centrifuges have reached the performance index of 400 hours for φ300mm centrifuges imported from Japan, realizing the localization of centrifuge materials.

Steering roller and pipe puller

Large-axis steering roller is a key component in the flat glass production device, it is the molten glass from the pool of vertical lead on, turn 90 °, into a horizontal stretching state into a solid flat glass sent to the annealing kiln, the steering roller and the flat pulling rollers are in direct contact with the molten glass, the surface temperature as high as 900 ~ 1,000 ° C. In 1991, the General Administration of Iron and Steel Research Institute of the Ministry of Metallurgy, the development and development of K60 nickel-based high-temperature alloy, and trial in Shunyi Glass Factory. In 1991, the Iron and Steel Research Institute of the Ministry of Metallurgy developed K60 nickel-based high-temperature alloy and tried it successfully in Shunyi Glass Factory, and the service life of the alloy was 1~2 times higher than that of the commonly used HK40 alloy. In recent years has been widely promoted throughout the country, the alloy in 1994 by the national invention patent. Horizontal glass pulling machine axis used to drive the rotating horizontal pulling machine, the axis encapsulated in the refractory material weighing about 200Kg rotating tube, under the action of 1050 ℃ high-temperature gas, to 6 ~ 15r/min speed rotation. 1981 years ago, Shanghai and Beijing Glass Instrument Factory introduced the Japanese NEG pulling machine production line, so far in China there are more than 30 production lines throughout the region. In order to realize the localization of pipe drawing machine materials and components, the General Research Institute of Iron and Steel of the Ministry of Metallurgy in 1983 made a trial of GH3007 high-temperature alloy horizontal pipe-drawing machine shaft (ø130mm x ф3000mm), used in the Beijing Glass Instrument Factory, the cumulative life of 13,522h, more than the imported Japanese HRA800 alloy shaft life of 10,386h.

 


Post time: Aug-05-2023