Is the faucet material all copper or copper alloy?

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There are many materials for faucets, such as stainless steel and copper. Is the faucet material all copper or copper alloy better? Let me take you all to find out.

The faucet is better to choose all copper material. The all-copper material can kill 99% of the bacteria in tap water. Even if the tap water bursts and causes foreign objects to enter, there is no need to worry about a bacterial infection; good metal-cutting performance reduces production costs, making it a must-have copper faucet for every household.

The main material of kitchen faucets currently used in China is brass HPb59, which contains trace amounts of lead. At present, the national faucet safety certification rules stipulate that the inspection should be carried out in accordance with the regulations, and the amount of lead precipitation should be less than or equal to 11 micrograms. At present, the lead-washing technology of big brands can inhibit the precipitation of most heavy metals.

The price of copper alloy faucets is much lower than that of full copper faucets, and this faucet is easier to produce on a large scale. The biggest disadvantage of alloy faucets is that they have no toughness and are prone to cracks after long-term use, and their service life is short.

Which is better, titanium alloy or stainless steel?

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Differences between titanium and titanium alloy and stainless steel

The density of titanium and titanium alloy is only 4.51, which is smaller than that of steel and only half the weight of steel, but its strength is similar to that of ordinary carbon steel. Titanium belongs to the thermodynamically unstable metal, which is very active. Titanium can form a natural oxide film (titanium dioxide) with air. This stable, strong adhesion, and good protective character oxide film determines the corrosion resistance of titanium, so titanium has excellent corrosion resistance. Next, it has a light texture, high tensile strength, and good mechanical properties.

Titanium alloys can be divided into corrosion-resistant titanium alloys, structural titanium alloys, heat-resistant titanium alloys, and low-temperature titanium alloys according to their applications.

1. It can be distinguished from color. Titanium is a little dark. It shows a cold color. I think it’s cool. Titanium is a little darker than steel. Steel is white, the pale kind. The two colors are very obvious.

2. It can also be distinguished by chemical methods, that is, soaking with nitric acid. Titanium does not react. The stainless steel will react strongly once it is put down. It is difficult to tell the difference between pure titanium and titanium alloy from the appearance.

3. Titanium can mark gray and black on ceramic tiles, but stainless steel cannot.

4. Good corrosion resistance of titanium: titanium alloy is easy to form a dense oxide film below 550 ℃, so it is not easy to be further oxidized. It has high corrosion resistance to air, seawater, steam, and some acids, alkalis, and soft media.

5. Good thermal strength of titanium: The melting point of titanium alloy is 1660 ℃, which is higher than that of iron. It has high thermal strength and can work below 550 ℃. At the same time, it shows good toughness at low temperatures.

6. Titanium processing is difficult: welding, electroplating, and cold stretching are very difficult. Welding and electroplating must be carried out in a vacuum or full of inert gas (vacuum ion electroplating)

Titanium alloys are widely used in various fields because of their high strength, good corrosion resistance, and high heat resistance.

The density of titanium alloy is generally about 4.51g/cm3, which is only 60% of that of steel. The density of pure titanium is close to that of ordinary steel. Some high-strength titanium alloys exceed the strength of many alloy structural steels. Therefore, the specific strength (strength/density) of titanium alloy is much higher than that of other metal structural materials, as shown in Table 7-1. Parts with high unit strength, good rigidity, and lightweight can be made. The engine components, framework, skin, fasteners, and landing gear of the aircraft are made of titanium alloy.

304 is universal stainless steel, which is widely used to make equipment and parts that require good comprehensive performance (corrosion resistance and formability). In order to maintain the inherent corrosion resistance of stainless steel, the steel must contain more than 18% chromium and more than 8% nickel.

The density is 7.93 g/cm3, also called 18/8 stainless steel in the industry. It has high-temperature resistance of 800 ℃, good processing performance, and high toughness, and is widely used in industry, furniture decoration industry, and food and medical industry.

Of course, titanium alloy is better than 304 stainless steel in terms of high strength, low density, and corrosion resistance

Several culprits of stainless steel rust

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Many people believe that stainless steel will not rust. In fact, everything has a life span. Stainless steel is also a kind of metal, which will be oxidized and corroded in nature, causing rust; The only difference is that the material or protection degree is different, which can delay the probability and time of rusting to the greatest extent. However, in many cases, stainless steel will also be “rusted”. Here are the main culprits of stainless steel rust:

1、 Presence of chloride ions in the service environment

Chloride ions mainly exist in purified liquids and gases. The use of stainless steel in the presence of chloride ions will accelerate its corrosion, even exceeding that of ordinary low-carbon steel. Therefore, there are requirements for the use environment of stainless steel, and it needs to be wiped frequently to remove dust and keep it clean and dry.

2、 Without solution treatment

Solution treatment: refers to the heat treatment process that heats the alloy to the high-temperature single-phase area and maintains the constant temperature, so that the surplus phase can be fully dissolved in the solid solution and then rapidly cooled to obtain the supersaturated solid solution. Its purpose is to fully dissolve various phases in the alloy, strengthen solid solution, improve toughness and corrosion resistance, eliminate stress, and soften, so as to continue processing or molding. If the alloy elements are not dissolved in the matrix material, the alloy content in the matrix structure is low and the corrosion resistance is poor.

3、 Natural intergranular corrosion

Under the action of a corrosive medium, a corrosion phenomenon between grains of stainless steel is called intergranular corrosion. When the stainless steel with intergranular corrosion is subjected to stress, it will fracture along the grain boundary and the strength will almost disappear. This is the most dangerous form of stainless steel damage.

Stainless steel will not rust because the content of chromium (Cr) and nickel (Ni) has reached a certain standard. These two alloys are the key to rust prevention in stainless steel. Generally, stainless steel produced by small factories will rust, mainly because of the low nickel content (the cost price of nickel largely reflects the benchmark price of stainless steel); If the nickel content reaches the standard required by various stainless steel, no matter how you cut it, it will not rust.

4、 Mechanical stress corrosion

When stainless steel materials are made into products, they need to go through such processes as stamping, shearing, punching, stretching, grinding, shearing, bending, planing, thermal cutting, or welding. Because of the external stress loading, the machined parts and their edges will be damaged by their own stress to a large extent, which will lead to the intergranular transformation; Therefore, it destroys its corrosion resistance and speeds up the rusting process.

5、 Damage to surface passivation protective layer

Passivation is a method to change the metal surface into a state that is not easy to be oxidized, thus delaying the corrosion rate of the metal. Passivation is due to the interaction between metal and oxidizing substances. During the interaction, a very thin, dense, well-covered, and firmly adsorbed passivation film is formed on the metal surface. Once this “protective film” is damaged by external forces (mainly large scratches), the stainless steel is like a body without resistance, which is easy to react with the outside world to rust and corrosion.

The application practice of stainless steel pipes tells you where the advantages are!

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Stainless steel material is a recognized healthy material that can be implanted into the human body and is used in almost all fields involving human health. It has been widely used. The Stainless steel water pipe is an environmentally friendly material that meets health requirements, can be 100% recycled, saves water resources, reduces transportation costs, reduces heat loss, and avoids sanitary ware pollution. The details are as follows:

1. Lifespan

Stainless steel tubing has the longest service life. From the analysis of the use of stainless steel abroad, the service life of stainless steel water pipes can reach 100 years, or at least 70 years, which is as long as the life of buildings.

2. Corrosion resistance

One of the most prominent advantages of stainless steel pipe is its excellent corrosion resistance, which is the best among all kinds of pipes. Because stainless steel can passivate with oxidant, a tough and dense chromium-rich oxide protective film Dr2O3 is formed on the surface, which can effectively prevent the further oxidation reaction.

And other metal pipes, such as galvanized water pipes and copper pipes, have little passivation ability, which is the key reason why the corrosion resistance of copper pipes of galvanized pipes is far less than that of stainless steel pipes. Stainless steel does not corrode uniformly like carbon steel, and no protective coating is required for use; with stainless steel water pipes, there is no limit to the chemical composition of water, because stainless steel has good performance in water of various oxygen content, temperature, PH and hardness Corrosion resistance; stainless steel water pipes can withstand high flow rates, even if the flow rate is greater than 40 m/s, it still maintains a very low corrosion rate, no more than 0.003 mm/year, especially suitable for high-rise water supply.

Stainless steel generally does not suffer from localized corrosion. The chloride content that 304 stainless steel can withstand is up to 200ppm, and the chloride content that 202 stainless steel can withstand is up to 1000ppm. This conclusion is based on exposure experimental data and has been confirmed by experience. The thermal expansion coefficient of stainless steel pipe is similar to that of copper pipe, which is 1.5 times that of ordinary steel pipe. Compared with stainless steel pipe, it has the characteristics of slow thermal expansion and cold contraction.

3. Heat resistance and heat preservation

The thermal conductivity of stainless steel pipe is 1/25 of copper pipe and 1/4 of ordinary steel pipe, especially suitable for hot water transportation. The most commonly used stainless steels in the water industry are 202 and 304 stainless steels, which can meet the vast majority of water treatment and delivery conditions.

4. Strength

The tensile strength of 304 stainless steel pipe is 2 times that of steel pipe and 8-10 times that of plastic pipe. The strength of the material determines whether the water pipe is strong, crash-resistant, safe, and reliable. Safety and reliability are the most important requirements for building water supply. Under the circumstance of being hit by an external force, the possibility of leakage of the stainless steel water pipe is extremely small. The working pressure of a high-rise water supply system is generally greater than 0.6Mpa, which requires higher pressure on pipes.

Let’s talk about steel.

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We recognize that, because of its critical role, people are interested in steel and the effect it has on the global economy. We are committed to being open, honest, and transparent in all our communications about our industry, its performance, and the impact we have.

Key facts:

The steel industry publishes data on production, demand, and trade at national and global levels, which is used for analyzing economic performance and making forecasts.
The steel industry presents its sustainability performance with 8 indicators on a global level every year.
The steel industry proactively participates in OECD, IEA, and UN meetings, providing all the information required on key industry topics which have an impact on our society.
The steel industry shares its safety performance and recognizes excellent safety and health programs every year.
The steel industry collects CO2 emissions data, providing benchmarks for the industry to compare and improve on.

How to prevent copper oxidation during copper alloy surface treatment?

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In the process of copper alloy surface treatment, after a period of storage, the surface of copper alloy will appear blackened and oxidized. After the surface of copper alloy is oxidized, it will seriously affect the quality, appearance, and service life of the product. In the process of copper alloy surface treatment, anti-oxidation treatment is a very important process. So, how to prevent copper oxidation during copper alloy surface treatment?

At present, the methods to prevent copper oxidation include passivation, electroless plating, electroplating, sealing, painting, and other processes. Among them, copper alloy passivation treatment is mature and easy to operate, which is favored by copper alloy surface treatment plants.
The copper alloy passivation treatment process includes copper degreasing, copper derusting, copper polishing, copper passivation, and other processes. The pretreatment degreasing and rust removal processes are very important, they determine the quality and yield of the final product, and the passivation process determines the role of rust prevention and discoloration prevention.

In general, copper alloy passivation agent is a chromium-free passivation agent with good environmental protection performance and stable physical and chemical properties.

Copper alloy passivation agent is non-toxic, odorless, non-volatile, non-deliquescent, non-decomposing, non-sublimating, and does not absorb dust and harmful gases such as H2S and SO2.

The copper parts treated with copper alloy passivation agent can effectively resist the erosion of copper alloys by hot and humid salt spray and bacteria, and have good wettability and high corrosion resistance.

The copper alloy passivation agent has the triple functions of dehydration, discoloration prevention, and rust prevention, and the generated passivation film has better electrical properties.

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If you encounter problems with other surface treatments of copper alloys, you can follow us and consult at any time. The editor must know everything!

The production process and welding quality of titanium plate determine its quality!

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A notable feature of titanium plates is their strong corrosion resistance, which is due to their great affinity for oxygen. It can form a dense oxide film on its surface, which can protect titanium from medium corrosion. It has good stability in acidic, alkaline, neutral saline solutions and oxidizing media, and is better than existing stainless steel and other commonly used non-ferrous metals in corrosion resistance.

The quality of titanium plate largely depends on the smelting process of the titanium plate manufacturer, including the chemical composition of titanium, the cleanliness of titanium water (gas, harmful elements, inclusions), and the quality of cast slab (composition segregation, decarburization, and surface conditions), which are the key control points of smelting operation.

In addition, industrial titanium plate also requires sufficient hardenability to ensure uniform microstructure and mechanical properties of the whole spring cross-section. The main reason for fatigue cracks is oxide inclusions in titanium, and the damage of type D inclusions to fatigue life is greater than that of type B inclusions. Therefore, foreign titanium factories and automobile factories put forward higher requirements for oxide inclusions in industrial titanium plates. For example, the Swedish SKF standard requires that the oxygen content in titanium be less than 15 × 10-6, and class D inclusions are lower than class B inclusions. Especially Al2O3 and tin inclusions do great harm to the fatigue life of titanium springs. In order to produce high-quality industrial titanium plates, special smelting methods such as electric furnace electro slag remelting or vacuum arc remelting were usually used in the past.

Because titanium plate has special physical and chemical characteristics, their welding process is very different from other metals. Titanium welding is a TIG welding process that effectively protects the welding area with inert argon. Before using argon, check the factory certificate on the bottle body to verify the purity index of argon, and then check whether the bottle valve leaks or fails.

When welding titanium plates, the following must be ensured:

The metal in the welding area shall not be polluted by the active gas n0h and the harmful impurity element clean above 250 ℃. Argon with purity not less than 99.98% and water content less than 50mg / M32: industrial grade I pure argon.

A coarse crystal structure cannot be formed. The welding process shall be carried out according to the predetermined construction sequence, and no large welding residual stress and residual deformation shall be generated. Therefore, the quality control of the whole process shall be carried out in strict accordance with the procedure quality management standards, so that the factors of human, machine, material, and method are under good control, so as to ensure the quality within a reasonable construction period.

Copper Nickel Alloy C71500 BFe30-1-1 Copper Rod Steel Plate Forgings

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Copper-nickel alloy C71500 cupronickel alloy is widely used in heat exchangers and condensing pipes for coastal power stations and ships due to its excellent corrosion resistance and anti-fouling properties. The excellent corrosion resistance of cupronickel alloy is attributed to the Cu 2 O film formed on its surface, which effectively prevents further contact between the substrate and the solution. As the main additive elements of cupronickel alloy, iron and manganese have an important influence on improving the corrosion resistance of cupronickel alloy, but there is no consensus on the influence mechanism of iron and manganese in it.

As a forgeable material, cupronickel alloy is suitable for both hot working technology and cold working technology and can be used to produce various profiles required. According to the processing process of cupronickel alloy, the maximum cold working deformation before annealing can reach 50%. The cupronickel alloy pipe is usually bent during use. When bending, the smooth bending method can prevent the influence of non-end flow on the service life of the pipe [DD. Under normal circumstances, the phenomenon of stress corrosion does not occur in cupronickel alloys, but when the cold working temperature is extremely low, stress relief heat treatment must be carried out, and the heat treatment temperature is 300 ° C ~ 400 ° C.

The complete annealing temperature of B10 alloy is 700℃~800℃, and the complete annealing temperature of B30 alloy is 750℃~850℃. The specific time and temperature of complete annealing depend on the degree of cold working, section thickness, degree of annealing treatment, and grain size of the alloy. Sure. Before heat treatment, the oily residue on the surface of the alloy must be removed to avoid the formation of the carbonaceous film. The carbonaceous film can cause pitting corrosion on the surface of the cupronickel alloy. Under certain working conditions, it will increase the sensitivity of impact corrosion, thereby reducing cupronickel alloy. Service time in practical application

Both B10 and B30 cupronickel alloys exhibit good resistance to seawater corrosion and biofouling under many conditions. Among them, the cupronickel alloy of B10 has better anti-biological accumulation ability. When the water speed is greater than 1m/s, the tiny organisms attached to the metal surface will be easily separated and removed. When the material does not have the ability to resist bioflooding, organisms in seawater will strongly adhere to its surface and grow in large numbers, resulting in a reduction in the service life of the material. Although some materials have good biofouling resistance, they do not have the ability to resist seawater corrosion, which will also reduce the service life. In addition, when the cupronickel alloy components in seawater are attached to the joints and surfaces of the components, the crevice corrosion resistance of cupronickel alloys is better than that of other common alloys. Cupronickel exhibits good corrosion resistance even under static or stagnant conditions that may occur during plant commissioning or overhaul

BFe30-1-1 cupronickel alloy has good solderability. However, this welding method is rarely used, because the joint strength obtained by this welding method does not meet the actual service requirements of cupronickel alloy, and the galvanic metal corrosion will be aggravated in a corrosive environment. Traditional brazing methods can be used, but a high silver filler metal is recommended, which minimizes the chance of corrosion of cupronickel. Copper-phosphorus and copper-silver-phosphorus solders should not be used because their use increases the risk of intergranular corrosion and hydrogen embrittlement. Re-cold-worked cupronickel alloy materials should be recrystallized and annealed before brazing to avoid excessive penetration and cracking between the brazing alloy and the base metal.

What is the difference between 316Ti stainless steel and 316L stainless steel?

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316Ti stainless steel is based on 316 stainless steel by adding Ti to improve the resistance to intergranular corrosion. It is also a variant of 316 stainless steel and is used in equipment resistant to sulfuric acid, phosphoric acid, acetic acid, and acetic acid. Physical properties: 316 stainless steel chemical composition C: ≤0.08 Si≤1.00 Mn≤2.00 P≤0.035 S≤0.030 Ni 11.00~14.00 Cr 16.00~19.00 1 Mo 1.80~2.50 Ti≥5*C%~0.70 Usually also called Mo2Ti3163 (00Cr17Ni14Mo2) is an ultra-low carbon steel of 0Cr17Ni12Mo2, which has better resistance to intergranular corrosion than 0Cr17Ni12Mo2 (SUS316). 316L stainless steel chemical composition C≤0.03 Si≤1.00 P≤0.035 S≤0.03 Ni: 12.0-15.0 Cr: 16.0-18.0 Mo: 2.0-3.0 Tensile strength (Mpa) 620 MIN Yield strength (Mpa) 310 MIN Elongation ( %) 30 MIN Area reduction (%) 40 MIN Features: due to the addition of Mo, its corrosion resistance, atmospheric corrosion resistance, and high-temperature strength are particularly good, and can be used under harsh conditions; excellent work hardening (non-magnetic); Excellent high-temperature strength; non-magnetic in solid solution state; cold-rolled products have the good gloss and beautiful appearance; compared with 304L stainless steel, the price is higher.

copper-nickel-90-10-pipe

UNS C70600 in Seawater Service

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