Main characteristics and uses of aluminum brass

/in /by

Special brass is formed by adding aluminum, silicon, manganese, lead, tin, and other elements into a copper-zinc alloy. Such as lead brass, tin brass, aluminum brass, silicon brass, manganese brass, etc.

Lead brass has excellent cutting performance and good wear resistance and is widely used to make clock parts, bearing shells, and bushes by casting.

Tin brass has good corrosion resistance and is widely used in the manufacture of marine parts.

Aluminum in aluminum brass can improve the strength and hardness of brass, and improve the corrosion resistance in the atmosphere. Aluminum brass is used to make corrosion-resistant parts.

Silicon in silicon brass can improve the mechanical properties, wear resistance, and corrosion resistance of copper. Silicon brass is mainly used to make parts for seagoing ships and chemical machinery.

What are the main characteristics of aluminum brass?

Aluminum brass has strong wear resistance. It has high strength, high hardness, and strong chemical corrosion resistance. There are also outstanding mechanical properties of cutting. Seamless copper tube drawn from aluminum brass is soft and wear-resistant. Aluminum brass seamless tubes can be used for heat exchangers and condensers, cryogenic pipelines, and submarine transport tubes. Manufacture sheet, bar, pipe, casting parts, etc. It contains 62%~68% copper and has strong plasticity. It is used to manufacture pressure-resistant equipment.

What are the uses of aluminum brass?

Aluminum in aluminum brass can improve the strength and hardness of brass, and improve the corrosion resistance in the atmosphere. Aluminum brass is used to make corrosion-resistant parts.

What are the components of aluminum brass?

Copper: 66.0 ～ 68.0

Sn: ≤ 0.2

Zinc: allowance

Lead Pb: ≤ 0.5

Phosphorus P: ≤ 0.02

Aluminum: 2.0 ～ 3.0

Fe: ≤ 0.6

Manganese Mn: ≤ 0.5

Antimony Sb: ≤ 0.05

Note: ≤ 1.5 (impurities)

What are the applications of aluminum brass?

The main alloy composition of aluminum brass is Cu Zn Al. In order to improve the strength, corrosion resistance, wear resistance, etc. of aluminum brass in practical application, elements such as As, Mn, Fe, Ni, etc. are often added to the alloy, thus greatly improving the comprehensive properties of the material. Due to the aluminum zinc equivalent coefficient 6 β The phase trend is large, and the strengthening effect is good. When the aluminum content increases γ Phase. Although the hardness of the alloy is increased, the plasticity is sharply reduced. In aluminum brass, the ionization tendency of the aluminum surface is greater than that of zinc. The dense and hard aluminum oxide film is preferentially formed to prevent the alloy from further oxidation and improve the corrosion resistance to gas, and solution, especially high-speed seawater.

Welding and testing of titanium alloys

/in /by

Weldability Analysis
Due to the high affinity of titanium alloys with O2, N2, and H2, the presence of these gases in the joints will make the joints brittle and reduce the impact performance, plasticity and toughness of titanium alloy welded joints. The presence of hydrogen in titanium alloys can cause delayed cracking in the heat-affected zone. When the amount of oxygen and nitrogen in the weld is high, the weld or heat-affected zone will also crack under the action of large welding stress, and the crack is also a delayed crack. Therefore, inert gas (or vacuum chamber) protection is very necessary. Due to the high cost of using a vacuum chamber, the method of inert gas protection is generally used. The main protective gases are helium and argon. Since the price of helium is higher than that of argon, generally speaking, for welding joints and heat-affected zones of titanium alloys that are not specially required, high-purity argon can be used for protection to prevent oxidation.

Most titanium alloys can be welded using oxyacetylene welding, and all titanium alloys can be welded using solid state welding methods (eg TIG, MIG, plasma arc, laser and electron beam welding). In fact, the tendency of titanium alloy welded joints to crack is much smaller than that of black metals (such as iron alloys, nickel alloys).

Although titanium alloys have such good properties and other excellent welding characteristics, some engineers still think that the welding of titanium alloys is quite difficult, mainly because the welding of titanium alloys has very high requirements for gas protection, and generally only very professional staff can Ensure that the gas protection meets the requirements. In fact, many welding methods can be used to weld titanium alloys.

Since the N2, O2 and carbonaceous substances in the air introduced during the welding process make the molten welded joint of the titanium alloy brittle, the area to be welded must be cleaned and protected with inert gas. The welding material is basically selected according to the characteristics of the material to be welded. The weldability of titanium alloys is generally evaluated based on the ductility and strength of the welded joint.

Laser welding titanium plate
The current application trend of laser welding of titanium alloys is more and more extensive, laser welding has small deformation, high production efficiency, and the degree of automation is higher than electron beam and TIG. Compared with electron beam welding, laser welding does not require complex equipment such as a vacuum chamber, so laser welding is more practical, and laser welding can be directly welded in different welding states.

Due to the high power of the CO2 laser, 25kW/h can be used to penetrate a titanium plate with a thickness of 20mm at one time. Nd:YAG lasers make YAG welding more flexible due to the ability to use optical fibers for energy transfer, but the penetration depth is limited due to the low power. It is easy to generate spatter during laser welding, which makes the surface unclean, and special care must be taken when post-weld treatment is not possible.

Post weld inspection
Visual inspection of titanium alloy welding parts is mainly to evaluate the quality of gas shielding. When the surface is silvery white, it means that the gas protection is very good; and when the surface is light yellow or dark yellow, it means that the titanium alloy is slightly polluted, but it is still acceptable; the surface is dark blue, which means that the pollution is serious, but due to the use of Different working conditions, some can be used; the surface is light blue, the pollution is serious, and it is almost impossible to use; when the surface is gray-blue or gray, the pollution is very serious and cannot be used; the same surface is white, the pollution is very serious, unavailable.

Color detection method
Hardness testing and eddy current testing can be used to detect whether the joint contains impurities. Since the properties of the joint will change when impurities are contained, the hardness and resistivity of the joint will be significantly higher when impurities are contained. The portable hand-held hardness tester can be used to test the hardness of weldments in situ. The application of this technology can easily detect the quality of welding. Under normal circumstances, the occurrence of welding cracks in titanium alloys is relatively small. However, cracks sometimes occur in the weld or due to inclusions. At this time, defects can be found by coloring inspection, and this method also has a certain effect on porosity. It must be noted that the colorant must be cleaned before proceeding with welding.

What are the properties of copper alloy casting?

/in /by

We all know that copper alloy casting has high hardness and good wear resistance and is widely used, so what are the functions of copper alloy casting? What are the functions of copper alloy casting for us today?
1. High hardness, excellent wear resistance, not easy to cause seizure, good casting function and cutting production function, and excellent corrosion resistance in the atmosphere and fresh water.
2. Good corrosion resistance, wear resistance and cutting production function, good casting function, high fineness of castings, and good air tightness
3. Corrosion resistance, especially for dilute sulfuric acid and fatty acid.
4. Good wear resistance and corrosion resistance, easy to manufacture, good casting function, and air tightness.
5. Copper alloy casting has good mechanical properties, corrosion resistance in the atmosphere, freshwater, and seawater, good casting performance, fine arrangement, good air tightness, good wear resistance, and can be welded.
6. It has good mechanical function and wears resistance, can be heat treated, has good corrosion resistance and oxidation resistance at high temperatures, and has good corrosion resistance in the atmosphere, freshwater, and seawater, and can be welded. crisp.
7. Copper alloy casting has good sliding properties and self-lubricating function under the condition of lack of lubricant and water-based lubricant, easy cutting, poor casting function, and good corrosion resistance to dilute sulfuric acid.
8. Copper alloy casting has good casting performance and wears resistance, good cutting performance, good corrosion resistance, and has a tendency to stress in seawater.

The New Egyptian capital represents a bold vision for smart cities

/in /by

Egypt’s ambitious new administrative capital is a large-scale infrastructure project on the edge of Cairo that will be crowned by Africa’s tallest skyscraper.

Halfway between the historic city of Cairo and the Gulf of Suez sits the as-yet-unnamed new administrative and financial capital (NAC) of Egypt. Still, under construction, the new metropolis already rises impressively from what was formerly a 700km2 expanse of desert 45km to the east of the Nile.

Cairo’s 20 million residents already make it one of the most crowded cities in the world, with the greater region’s population expected to double over the next 20-30 years. The new city is expected to ease congestion and boost economic development as part of the Egypt Vision 2030 program.

Designed to accommodate the country’s main government departments and ministries, as well as foreign embassies, the NAC will house a population of 6.5 million once completed.

A steel-built oasis

Planned to support 21 residential districts and 25 ‘dedicated’ districts, the city will boast a sprawling central park with artificial lakes and a steel and concrete composite-built ‘green river’ that will run through the NAC, mimicking the path of the Nile through Cairo.

The city will also feature 2,000 educational institutions, more than 600 hospitals, and clinics, a technology, and innovation park as well as a huge theme park that will be four times the size of Disneyland.

The city will play host to the new national stadium, a 93,000-seater which will be the second largest in Africa once completed. The stadium roof, which will be supported by a high-strength steel truss frame and steel suspension cables, is designed to resemble the ceremonial headdress of Queen Nefertiti.

The NAC’s business district is home to Africa’s tallest tower – The Iconic

The valley of the skyscrapers

At its heart will be the NAC’s downtown, a newly developed cluster of skyscrapers that will be home to the city’s business district. Looming over the skyline is the city’s pinnacle, the glittering Iconic Tower.

Standing 394m tall over 78 floors and two basement levels, the Iconic is Africa’s tallest tower. Inspired by the 3,000-year-old Obelisk of Luxor, the building comprises 40 floors of offices, and 10 high-end apartments, with another 30 for a five-star hotel with a 74th-floor observation deck that offers unparalleled views of the new cityscape.

The tower was constructed by the China State Construction Engineering Company, which had the challenge of laying the supertall structure’s foundations into the basalt rock which lies underneath the NAC.

The Iconic Tower is formed of a composite steel structure grounded on a reinforced concrete raft that sits directly on the rock surface. Safely supporting the full weight of 78 floors requires 4,600 tonnes of high-strength steel reinforcement and the new tower’s foundations are rock solid.

Making connections

Connecting and powering an entirely new city is a massive undertaking, with huge engineering works needed to provide sewers, power cables, and roads to the NAC’s desert location.

90 square kilometers of solar energy farms slated for development in the nearby desert allowed planners to take advantage of the high levels of solar activity the region experiences, with the aim to provide up to 35% of the city’s energy needs.

450km of high-strength steel rail will be laid and operational by 2023, with an expected 1,750km expansion later connecting the new capital with the city of Aswan

Egypt has also teamed up with Siemens to deliver a high-speed rail line that will extend from El Alamein on Egypt’s Mediterranean coast through the NAC to Ain Sokhna on the country’s Red Sea coastline.

The 450km of high-strength steel rail will be laid and operational by 2023, with an expected 1,750km expansion later connecting the new capital with the city of Aswan on the edge of Lake Nasser in Egypt’s south.

Egypt’s new capital city is founded on the skills of the design and engineering teams that make infrastructure projects like this possible. Those teams in turn needed materials they could rely on to realize their ambition – an innovative steel-built city towering above the desert.

The difference between 316L stainless steel and 2205 duplex stainless steel

/in /by

316L stainless steel is widely used in the chemical industry because of its excellent corrosion resistance. 316L stainless steel is also a derivative of 18-8 type austenitic stainless steel, with 2~3% molybdenum added.Nitrogen is added to 2205 duplex stainless steel to improve local corrosion resistance. Its solid solution structure accounts for about half of ferrite and austenite. Generally, the minimum phase content needs to reach 30%, so it has ferrite. Performance characteristics of bulk and austenitic stainless steels.

From the above point of view, 316L stainless steel and 2205 duplex stainless steel are two different stainless steel materials. The question is, which stainless steel has more advantages? What about the downside? The following ZTE Yide Xiaobian will tell you about it.

The differences between 316L stainless steel and 2205 duplex stainless steel are as follows:

1. The yield strength of 2205 duplex stainless steel is more than double that of 316L stainless steel, and it has enough plastic toughness for forming. The wall thickness of the pressure vessel made of 2205 duplex stainless steel is 30-50% lower than that of 316L stainless steel, which is conducive to reducing costs.

2. 2205 duplex stainless steel has excellent resistance to stress corrosion cracking, especially in the marine environment containing chloride ions, stress corrosion is a prominent problem that is difficult to solve for austenitic stainless steel including 316L stainless steel.

3. In many media, the corrosion resistance of 2205 duplex stainless steel is better than that of ordinary 316L stainless steel, because duplex stainless steel has extremely high corrosion resistance, such as acetic acid, formic acid, etc. It can even replace austenitic stainless steel and even corrosion resistance alloy. However, it is still necessary to choose 2205 duplex stainless steel or 316L stainless steel according to environmental requirements and cost.

4. It has high strength and good local corrosion resistance, and its wear resistance and corrosion fatigue properties are better than 316L stainless steel.

5. The linear expansion coefficient of it is lower than that of 316L stainless steel, and it is close to carbon steel. It is suitable for carbon steel connections and has important engineering significance.

6. Whether under dynamic or static load conditions, 2205 duplex stainless steel has a higher energy absorption capacity than 316L stainless steel, which has obvious advantages and practical application value for structural parts or pipelines to cope with sudden shocks, explosions, etc.

Having said so much about their differences, it seems to have more advantages than 316L stainless steel, but does it have any disadvantages? Wuxi ZTE Yide Xiaobian tells you, yes. Compared with 316L stainless steel, the disadvantages of 2205 duplex stainless steel are as follows:

1. The universality and versatility of 2205 duplex stainless steel are not as good as that of 316L stainless steel. For example, for long-term applications, the temperature of the medium used must be controlled below 250 degrees, and only 316L stainless steel can be competent.

2. The plasticity and toughness of 2205 duplex stainless steel are lower than that of 316L stainless steel, and the cold and hot processing technology and forming performance are also poor.

3. It has medium temperature brittleness, and it is necessary to strictly control the processing system of heat treatment and welding to avoid harmful phases and damage performance.

4. The main reason for the weakness of duplex stainless steel compared with austenitic stainless steel is that 2205 duplex stainless steel contains a large amount of ferrite.

Will medical alcohol and edible alcohol cause harm to 304 stainless steel water cups?

/in /by

Stainless steel water cups cannot hold acidic beverages. Acidity and alkalinity will cause corrosion of the inner wall of the 304 stainless steel water cup. Will medical alcohol and alcohol consumption cause corrosion damage to the stainless steel water cup?

First of all, let’s understand the composition of alcohol and 304 stainless steel. The main component of alcohol, alcohol, is an organic substance composed of three elements: carbon, hydrogen, and oxygen. It has the characteristics of evaporation and melting. At the same time, alcohol with higher concentrations will also produce chemical changes to metal materials, plastics, and plastics. 304 stainless steel is a practical 304 stainless steel. The main components are C≤0.08%, Si≤1.00%, Mn≤2.00%, 8%≤Ni≤15%, and 18%≤Cr≤20%. It has good characteristics and mainly reflects in formability and corrosion resistance.

If you simply master the composition of alcohol and 304 stainless steel, you will find that alcohol with a higher concentration is corrosive, while the content of medical alcohol is only 75%, and the content of food-grade plastic alcohol will be lower, so the difference between medical alcohol and food-grade plastic alcohol Corrosion will be almost zero. At the same time, the 304 stainless steel plate has good corrosion resistance, so medical alcohol and food-grade plastic alcohol will not cause corrosion to the inner wall of the 304 stainless steel water cup.

Russia researches to improve the durability of aviation Ti-6Al-4V titanium alloys

/in /by

Two-phase titanium alloys are widely used in aerospace and engine manufacturing due to their high specific strength and corrosion resistance, but improving their durability is a pressing task in the development and production of gas turbines engine components, such as compressor blades and disks, will bear a large tensile load during operation.

At present, two-phase submicrocrystalline titanium alloys have been widely used in the world to manufacture gas turbine engine components operating under high cyclic loads and high-temperature environments of 201-351 °C. But so far, the fatigue strength of titanium alloys in this working temperature range has not been studied. Scientists from the Faculty of Mechanics and Technology of the Perm University of Technology studied the properties of the Ti-6Al-4V alloy composed of aluminum, vanadium, and titanium and evaluated the alloy’s performance at a maximum temperature of 351°C.

According to the researchers, the test was carried out using hot-rolled Ti-6Al-4V alloy bars with a diameter of 20 mm, which underwent standard heat treatment: hardening at 966 °C and annealing at 676 °C for 4 hours; At the temperature of 651°C, the rods were processed by four equal-diameter angular extrusions; finally, the mechanical tensile tests were carried out at room temperature and 351°C.

All samples used for fatigue testing were made by turning and mechanical polishing and the microstructure of the material was analyzed in longitudinal sections of the rod using transmission electron microscopy.

Compared with the coarse-grained alloy, the Ti-6Al-4V ultrafine-grained alloy obtained by equal angular extrusion exhibited higher tensile strength and higher strength at the working temperature of 351 °C. The research was carried out within the framework of the Academic Strategic Leadership Programme “Initiatives-2030” in accordance with the national mandate. In 2021, Perm University of Technology received a grant of 100 million rubles from the “Initiative-2030” program. “Initial-2030” is the largest program in Russian history to support and develop higher education institutions.

Customer orders in Serbia have been successfully delivered

/in /by

As many people traveled to Xinjiang and Tibet from June to July this year, which led to a new round of epidemic outbreaks and brought us many interruptions, which seriously affected the delivery date we agreed with our customers.

Our customers were facing a lot of pressure due to the urgent need for goods from end users. The customer kept pushing us and we pushed our factory to speed up the progress every day.

After much cooperation, finally, after 2.5 months of intense production, we successfully shipped the goods on October 17, 2022, helping our customer to solve the urgent need, and our customer was very happy. The road ahead in life is always full of thorns, bends, and surprises.

Here are the photos of the goods to share with you:

If you have ASTM A179, A192, A210 A-1/C, A213 TP304/304L, TP316/316L, T5/T9/T11/T22, A334 Gr.1/3/6, 09CrCuSb, welcome to contact us. Email: [email protected]

What is the corrosion resistance of pure nickel NICKEL200?

/in /by

Nickel base alloy has excellent corrosion resistance, and has high corrosion resistance in many substances and even strong corrosive substances. Nickel base alloys have excellent physical and technological properties, but they are generally not used casually because of their high price. However, due to the development trend of high main parameters (temperature, working pressure, material concentration) in the whole process of chemical plants, there are more and more places with strong corrosivity, and the corrosion standards are becoming more and more strict. Therefore, the common machinery and equipment are not only required to be resistant to overall corrosion but also more and more resistant to pitting, stress corrosion, gap corrosion, etc. When selecting raw materials, we should not only consider the one-time project investment cost but also consider the maintenance, depreciation, shutdown loss, and other costs and their safety factors. Therefore, we pay more attention to the stability of the long-term operation of machinery and equipment. This element promotes the use of nickel-based alloys with high corrosion resistance.

At present, most of the nickel base alloys commonly used in the processing and manufacturing industry adopt the models of international standards. Therefore, the following is dominated by the American nickel base wrought aluminum alloy, and a brief and detailed introduction to pure nickel is given.

Pure nickel has good corrosion resistance in hot concentrated alkaline solution, does not cause alkali ductile stress corrosion cracking, and has good corrosion resistance to water, seawater, high- temperature dry fluoride, but is not corroded by oxidizing acid, aqueous solution with reducing agent and most of its molten metal materials. It can corrode and become brittle in gas with high-temperature sulfur content. With the increase of nickel content in stainless steel and nickel base alloy, the corrosion resistance in dilute hydrochloric acid, sulfuric acid, and ammonium sulfate is significantly enhanced, and the stress corrosion resistance in sodium hydroxide solution is also significantly enhanced. The corrosion resistance in caustic soda solution is basically positive correlation with nickel content.

For a pure nickel, the market generally includes NICKEL200 and NICKEL201

NICKEL200 COMPOSITION:

Carbon C ≤ 0.15

Silicon Si ≤ 0.35

Manganese Mn ≤ 0.35

Sulfur S ≤ 0.01

Nickel Ni+Cobalt Co greater than or equal to 99

Copper Cu ≤ 0.25

Fe ≤ 0.4

NICKEL200 is mainly used to solve the problem of oxidizing halogen system vapor, alkali solution, non-reducing acid salt, organic acid, and other machinery, equipment, and components. In the application, the temperature should be less than 315 ℃ in the natural environment. NICKEL200 corrosion resistance: corrosion is relatively slow in the air, and HCl has excellent corrosion resistance in various sulfuric acids in the sea. However, it should be used cautiously in HIC acid with high water flow. It is not easy to use in H3PO4 and HNO3. It has very good corrosion resistance in H2SO4, which is only used to block gas, in HF without water at high temperature, in chlorine and HCl at high temperature, and in chlorine and fluorine.

Welding method of 316L stainless steel round steel

/in /by

The most commonly used welding method for 316L stainless steel round steel is manual welding. The most commonly used welding method for stainless steel is manual welding (MMA), followed by metal gas-shielded welding (MIG/MAG) and tungsten inert gas-shielded welding. (TIG).

Preparation before welding: The thickness of 4mm or less does not need to be broken, and it is directly welded, and one side is welded through once. Butt welds with a thickness of 4 to 6mm can be welded on both sides of the joint without opening. More than 6mm, generally open V or U, X-shaped groove.
Next: Degrease and descale the weldment and filler wire. to ensure welding quality.

Welding parameters: including 316L stainless steel round steel welding current, tungsten electrode diameter, arc length, arc voltage, welding speed, shielding airflow, nozzle diameter, etc.
(1) Welding current is a key factor in determining weld formation. It is usually determined according to the weldment material, thickness, and groove shape.
(2) The diameter of the electrode is determined according to the size of the welding current. The larger the current, the larger the diameter.
(3) Welding arc and arc film, the arc length range is about 0.5 to 3mm, and the corresponding arc voltage is 8~10V.
(4) Welding speed: The selection should take into account factors such as current size, weldment material sensitivity, welding position, and operation mode.

The above is the welding method of 316L stainless steel round steel that Xiaobian shared with you today, I hope it can be useful to everyone!