Durable and rust resistant window screen mesh for commercial and domestic environments

Heanjia’s Window mesh screens offer the comfort of fresh air flowing in your home with clear outdoor views. The strength and durability of screen offer the peace of mind knowing that your house is protected.

Made from durable stainless steel grades, the window screens introduce innovation in the security products. They are configured by using a unique patented pressure process, preventing the use of screws, rivets, pins etc to keep the mesh panel. It also prevents any dissimilar metal surfaces coming in contact of each other hence preventing wear and tear.

It is feasible to keep the inside of your house protected with virtually invisible screens that help to keep your areas free of bugs and insects. You can enjoy the comfort and get peace of mind knowing that your house is secured with the advantage of strong and durable mesh screens.

Our mesh screens are widely loved and demanded by architects. These are a durable product with contemporary designs that make it easy to find supreme security screens that fit easily in your home.

Sleek designs never compromise with security. Our security mesh screens incorporate patented stainless mesh system with heavy duty frame for enhanced strength. The multiple panel system can be configured to open in or out and keep screen side by side when open.

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The window mesh screens are designed and tested to prevent unwanted intrusion in your home via windows in addition to providing you and your family an easily escapable way in case of fire or other critical conditions that may occur at your home. The slim line design has a simplistic and effective opening way that can prevent any accidental disengagement.

Features of Advanced window mesh screens

Meet the latest standards

Provide uninterrupted clear views

High strength and durability

Advanced innovation

Access to glass for easy cleaning

Resistance to rust and corrosion

Made from highly tensile materials

Designed to become your natural choice to have a security screen that does not compromise your architect, we offer mesh screens to compliment you and your house with a full selection of security screens to suit individual tastes. When you choose your window screen, you are enjoying an assistance of the world’s expert window screen supplier. Our screens are rigorously tested to ensure they meet various industrial standards. We manufacture a range of insect screens for commercial and residential application. These screens are used in place where intrusion of insects is required to prevent for the comfort and hygiene and where natural airflow is required such kitchens, restaurants, hotel and accommodation area, factory cafeteria, main entrances, dining rooms, living rooms and bedrooms.

Contact our experienced window screen supplier to meet your screen needs for your specific application.

Crevice corrosion resistance of Hastelloy and Inconel alloys

Inconel and Hastelloy grades have major applications in corrosive environments. Chromium concentration in both of these alloys and molybdenum in Hastelloy alloys have a crucial role in providing corrosion resistance. Addition of molybdenum to Hastelloy modifies the nature of surface from one comprising a susceptible nickel oxide to the one possessing highly corrosion resistant surface comprising mainly chromium oxide. Oxides of chromium decrease the crevice rate and enhance the resistance to it.

How does crevice occur?

 Crevice usually occurs when one material is placed in contact with another. The second material could be a component for example connection like a fastener made from the same material or different material. We consider second material as an elastic band that develops crevice where deposits of mud and oxides and other solid particles that leave precipitates on the surface of alloy test sample. Corrosion due to crevice is caused by exposure to the atmosphere or by retaining water, the other surface beyond the crevice can draw off and dry. Crevice corrosion by metals is a similar mechanism to pitting.

Consideration of crevice corrosion is essential during material selection, particularly when the environment is highly corrosive. Various alloys like stainless steels, Inconel and Hastelloy alloys are widely used in aggressive conditions, whilst there is some sensitivity to crevice and pitting corrosion, the extent of corrosion and degradation is based on the proportions of alloying elements and the concentrations of the corrosive media.

Both Inconel and Hastelloy alloys samples are immersed in water bath corrosion testing equipment at 60oC for a month. Final sample preparation included polishing with 600 grit papers thereafter degreasing in a detergent solution and drying prior to immersion in the electrolyte bath.

Every sample is tightened with an elastic band at the center before being kept in a beaker comprising 3.5% solution of sodium chloride. A lid was placed on every beaker with sufficient pressure to clamp the elastic hand used to suspend the sample to prevent cutting the elastic band. The effect of the proportion of alloying elements in these alloys can only be observed when crevice corrosion occurs at or below 60oC. The extent of surface hardness, the materials and tightening procedures are used to create crevice effect the test results.

Temperature has an essential role in crevice corrosion. With increase in temperature, the beginning of crevice corrosion and thereafter its propagation in the crevice and mass transfer are accelerated. Nickel alloys are not much used in the corrosive conditions because they soon lose their passivity and experience crevice and pitting corrosion.

Microscopic observation by using scanning electron microscopy shows a crevice corrosion region in the Inconel sample. The difference between the component of the sample surface unaffected by the crevice corrosion and the part influenced by the crevice corrosion is easily observed.

The development of a passive layer on the surface usually occurred in both alloys tested in 3.5% sodium chloride solutions. When molybdenum precipitates on the surface as an oxide within a pit it delays and prevents further pitting.

Hastelloy although shows no sign of crevice corrosion on the sample surface. Hence performance of Hastelloy wire with chromium and molybdenum additions attains better crevice corrosion resistance as compare to Inconel alloy. The crevice corrosion temperature for Inconel and Hastelloy is issue to extrapolate from these outcomes and become more complex corrosion process as compare to it is in room temperature.

Different types of industrial corrosions that should not be ignored

Pitting

Pitting corrosion is a type of galvanic corrosion in which chromium in the security layer is dissolved leaving behind the corrosion susceptible iron.  Pitting corrosion of stainless steels usually occurs in acid chlorides. They react with chromium to develop the soluble chromium chloride. Hence chromium is eliminated from the passive layer leaving behind the active iron. When chromium is dissolved, the electrically driven chlorides bore in the stainless steel developing a round pit. The residues in the pit are highly corrosive to stainless steel. While using molybdenum or nitrogen as an alloying element, the resistance to pitting in stainless steels enhances.

With increase in molybdenum concentration in an alloy, its resistance to pitting increases at a higher rate. So, molybdenum and chromium based alloys are known to provide outstanding resistance to pitting.

Crevice corrosion

It is another commonly occurring galvanic corrosion that attacks a metal when it is close touch of a crevice agent. Crevice corrosion is easy to identify and determine as when and where it will occur. Similar to pitting condition, a conductive fluid should be available, moreover if chlorides occur , the corrosion rate accelerates. Crevice corrosion is based on the environmental temperature, alloy composition and metallurgical type of an alloy. So, there is a connection between the tightness of a crevice and extensiveness of corrosion. A limit called critical crevice corrosion temperature (CCCT), below which the metal is not attacked.

With increase in difference between critical temperature and service temperature, the chances of occurrence of crevice corrosion increase. Although the effect of temperature is not much clear for crevice, but increase by 60oC or 100oF to CCCT, the pitting can be identified.

Intergranular corrosion

The metallic materials comprise small grains that are oriented in a random manner. Due to their random orientation of the grains, there is a variance among atomic layers where the grains meet which is called a grain boundary.

Carbides are developed when heating occurs, for example welding, heat processing or metal production. Understanding the mechanism of carbide formation can help to find ways to prevent it. For instance, using low carbon grade of stainless steel during welding. Use of these grades is very common in these days because they are made by using argon-oxygen-decarburization refining and all steels are made by using this method as it allows precise control of the alloying elements for example 304L and 316L. The best way is to use a stabilized grade. These grades should be used when the steel is kept for long durations in the temperature range of 800 – 1500oF or 425oC to 800oC.

The stress factor is more fine. Stress should be tensile and exceed the yield strength of the component. When physical pressure is applied the material on a fixed shape, the yield strength exceeds. But situations can be made complicated by stress increasing aspects. Here to overcome these conditions, it is recommended to use high nickel alloys for example Nickel Inconel bars and Monel bars. Corrosionresistant Monel bars are fit for use in stress conditions.

Application of corrosion resistant alloys in deep sea downhole conditions

High strength corrosion resistant alloys for deep sea downhole applications have been in use since 1980. Although cold processed nickel chrome alloys were used in tubing forms, their machining into complex components was not possible. Further low alloy and stainless steels were used, Monel k500  was also used for high strength and corrosion resistance, however it was corroded in hydrogen sulfide conditions at high temperatures. In fact nickel-chrome alloys  received corrosion in this field. Oil applications needed subsurface protective vales that could deal with temperatures up to 150oC and pressures up to 140MPa. For this precipitaton hardened Inconel 718 was used for its excellent properties.

Nickel alloys are austenitic in nature and are widely engineered to enhance their microstructures. However the composition of these alloys varies extensively, there are major compositional elements such as iron, cobalt, tungsten, molybdenum, chromium, and rhenium.

Inconel alloy 718 is popular for its outstanding performance at high temperatures and resistance to mechanical and chemical corrosion. It has large grains and a clean microstructure. The microstructure and hence the function of an alloy are determined by its development and processing background. Aging cycles fine-tune the microstructure for specific applications.

The melting and casting processes provide an initial microstructure with the precipitation of secondary phases. These processes need careful control because it is not easy to dissolve few precipitates with the after heat treatments. Inconel 718 is often vacuum induction melted and remelted through vacuum arc remelting and electro slag remelting. The remelting process manages improves the uniformity and purity of the microstructure. High temperature and forging treatments are used to organize the microstructure by dissolving second phases to undo segregation that occurs during solidification.

Heat processing methods are applied to achieve a specific property of an alloy. Inconel 718 is processed via two types of methods: Direct Ageing and solution annealing with double ageing processing. Direct ageing enhances the strength but it cannot dissolve the harmful precipitates.

Inconel 718 is heat treated by: annealing up to 1040oC for approx 1 hour, water cooled and precipitation hardened up to 800oC for ten hours and furnace cooled to bring temperature down to 650oC for 8 hours. The annealing temperature of this material is slightly higher to increase the magnitude of dissolved precipitates. After, aging processing is performed to enhance the gamma double prime precipitation.

Nickelbased superalloy Inconel 718 offers outstanding resistance to localized corrosion, intergranular attack and SCC. The extent of resistant is based on the alloy’s microstructure and composition. It is hence essential to consider the compositional elements of nickel alloys and their effect on the corrosion resistance.

Nickel prevents chloride based SCC and molybdenum and copper prevent corrosion in reducing conditions. Chromium prevents localized attack by developing chromium oxide layer.

Materials used in oil and gas plants are exposed to sulfur based conditions for example hydrogen sulfide in downhole pipes. These conditions cause sulfide corrosion and attack the alloys at the higher rate. To prevent this corrosion, nickel alloys with higher chromium content should be used.

Tungsten mesh heater- A largely used material for furnaces

Tungsten mesh is a recommended material for use as a furnace heating component. By virtue of its outstanding properties, tungsten mesh withstands multiple heat cycles without degradation hence providing long service life. A large surface area provides good watt density and resistance can be adjusted to increase efficiency.

Tungsten is known to be easily oxidized even at moderate temperatures. Tungsten basis heater brings the revolutionary performance. Offering comfort over traditional portable heater while fueled by same gas cylinder, the tungsten basis heater provides directional and evenly heating in an effective and efficient manner.

Tungstenmesh’s unique properties maximize the heater performance while providing superior heat distribution. Tungsten mesh screen provides significant wind resistance when combined with double thermocouples, providing suitable service in winds running at speed of 12 km/h.

High temperature heating Tungsten mesh known for its high melting temperature is widely used in manufacturing high temperature furnaces, heating elements and insulation screens. Tungsten heating mesh can be used up to 2800oC or 5070oF in vacuum.

How to choose a furnace heating element

The commonly used materials for furnace manufacture are tungsten, molybdenum and tantalum. These metals are also widely used as racks, skids and boats for material processing for example sintering, annealing and vacuum brazing. Advantages of refractory metals comprise good electrical properties, low vapor pressure, low electrical resistivity and nominal heat capacity. A crucial property of a refractory metal is low thermal capacity. A furnace heating element with low heat capacity quickly heats up and cools down. Energy savings are ensured because heat does not waste during heating the materials.

Tungsten also provides outstanding resistance to molten glass hence is fit for use with dies and mandrels and as electrodes in the melting operations. While choosing a refractory metals for furnace applications, service conditions and properties of the product under processing is also considered. Tungsten is the most commonly used refractory metal in furnace conditions. The refractory metals are readily fabricated by traditional methods but tungsten is difficult to fabricate. It has major applications in high temperature applications up to 2800oC in inert or protective and reducing conditions. At such high temperatures, it is challenging to insulate the hot region. It is common to use tungsten in a vacuum or low partial pressure condition.

Tungsten mesh in the finished form inherits the properties of tungsten providing outstanding heat resistance and electrical resistivity. It is widely used for radiation shielding and as a heating element for vacuum furnace. For its outstanding corrosion resistance, it is used as filter or sieve material for service in acid and alkali environments.

Major application fields of Tungsten mesh include: acid production, filtration, heat shielding, electronics, battery, vacuum equipments, chemical plants and science research labs. Tungsten mesh when used in heaters is formed and welded. It is highly durable and can withstand higher temperature above 2000oC. For its excellent properties, Tungsten mesh is largely used in the construction and design of components for high temperature furnaces. Tungsten mesh heater provides high performance radiant heating to outdoor and semi-enclosed areas. Its high temperature performance makes it usable in all conditions.

Use of Nickel based super alloys for heat pipes

There are various applications that use heat pipes in the moderate temperatures of 450K to 750K such as space nuclear power system radiators, fuel cells, geothermal power, waste heat recovery units and high temperature electronics cooling. Various life tests have been conducted at temperatures of 673K using Hastelloy B3, C22 and Hastelloy C2000, Monel 400 and Monel K500. The test fluids are evaluated and regions of the heat pipes are analyzed to determine the magnitude and type of corrosion in the heat pipes. It is found that Monel heat pipes are suitable for service up to 550K. Copper depleted zones and copper surface nodules developed on the Monel 400 screen wick however not on the Monel K500. Hastelloy B3, C22 and C2000 at 673K were suitable. Alloy C2000 received nominal corrosion when used with titanium tetrachloride. On the other hand, Hastelloy C22 attained 5 to 10 micro-m thick double corrosion layer when evaluated with AlBr3 service fluid. The outcomes show that the tested envelope materials and service fluids can develop feasible material- service fluid combinations.

There is no commonly accepted service fluid over the whole intermediate temperature zone. Likely service fluids comprise elemental working fluids like sulfur, organic compounds and halides. Intermediate temperature based heat pipe life analyses were conducted for 40 years to find suitable working fluid and envelope combinations.

Monel water heat pipes

Various water working fluid heat pipes made from Monel K500 and Monel 400 are tested at different temperatures for different durations. While Monel 400 heat pipes offered suitable service, there were also some surprises found with these tests. Wide changes such as the development of dark subsurface layer and bright nodules were found in the alloy. Although the variation was the most extensive for the Monel- water heat pipes, Monel 400 wire mesh’s morphology was also typical. On the other hand, Monel K500 does not show wide change. Close test of the envelope exhibits a nominal corrosion. Inclusion of various elements to Monel K500 seemed to stabilize the alpha phase and inhibit this degradation. While no large magnitudes of oxygen were noticed, preferential oxidation of Nickel may also have played significant role in the development of the observed morphology and phases. Both Monel 400 and K500 are widely used in steam plants.

Hastelloy C alloys for heat pipes

Hastelloy C2000 and C22 are used with TiCl4, AlBr3, SnCl4 and other heating fluids. Alloy C2000 made a wide reaction with SnCl4. On the other hand, Hastelloy C22 provided significant performance in the heating fluid media and took a considerably long time to build up the corrosion layers.

Hence these Nickel based alloys are found to be suitable for the heating pipe materials for providing outstanding performance in the vigorous conditions. They prevent corrosion in the significantly long time and found to be consistent with the working fluids.

High corrosion resistant materials for fluorine based applications

Fluorine is the strongest oxidizing agent among all chemical elements. It is used in large magnitudes on an industrial and lab scale in atomic energy sector. Fluorine also develops the most stable metal fluoride layers. In alloy selection, the diffusing element in the alloy must develop only single and nonvolatile fluoride. Different metals provide different levels of corrosion resistance. Nickel offers the best corrosion resistance while the steel provides nominal performance.

Suitable choice of materials of construction is important for the safe operation of any system or piece of equipment. The common metallic materials of construction for use with fluorine near room temperature or below about 250oF are steel, Monel, nickel and aluminum. These materials develop thin, protective corrosive layers and are more corrosion resistant as compare to others. Iron and steel are the common commercial storage container materials: Monel and Nickel provide the best performance as systems, tubing and are preferred for high temperature operations. Copper tubes are useful in various applications, particularly near room temperature, although with increase, its reactivity more increases as compare to Monel and Inconel.

In alloy selection, the diffusing elements in an alloy should develop only single stable and nonvolatile fluoride. Using nickel based alloys, the fluoride layer developed is NiF2. The chosen alloy should be single phase because in multiple phase alloys, one phase is attacked at a higher rate and it rapidly attains intergraular corrosion and stress corrosion cracking. One phase should be leached out fully. Alloys may become incompatible at lower temperatures as compare to resistant basic metal. Intermetallic compounds are attacked faster as compare to pure component.

While using less resistant materials, it is recommended to plate the metal with a resistant metal. Use of electroplated nickel is best. On the other hand, while using Monel400 for fluorine based processes, the layer formed is a mixed fluoride of the major alloy compositions of approximately the composition of the alloy. For nickel 200, the fluoride layer is fluoride of the main element.

Metals for Fluorine based rocket fuels

In aerospace applications where propellants considered for storage in space at temperatures below -200oF include fuels like oxygen difluoride, fluorine-oxygen mixtures and chlorine trifluoride. The recommended metals and alloys for use for this application are aluminum, nickel, copper, titanium and stainless steels. These materials are found suitable for construction of equipments for storage and handling the semicryogenic propellants for duration of two to ten years. These high functional materials are found to provide suitable physical properties at extremely low temperatures, resist corrosion and corrosion as well as not to induce propellant decay.

Corrosion rates of Nickel based alloys are very low in fluorine based solutions and environments. Therefore these alloys are recommended for use in these applications. These materials are sturdy, durable and corrosion resistant that they can withstand fluorine based conditions at various temperatures for long period. So contact Heanjia Super-Metals for finding more information about these materials and choosing a suitable one.