When selecting stainless steel in corrosive environment, in addition to having a detailed understanding of the specific service conditions of stainless steel, the main factors to be considered include: corrosion resistance, strength, toughness and physical properties, processing, formability, resources, price and difficulty of obtaining.
Corrosion resistance includes rust resistance and resistance to acid, alkali, salt and other corrosive media, as well as oxidation resistance, vulcanization, chlorination and fluorination at high temperature. Since different stainless steels are mainly selected to solve various corrosion problems encountered in practical engineering, how to improve the corrosion resistance of stainless steel in corrosive environment is the first thing to be considered by material selection personnel. Corrosion is the damage caused by chemical or electrochemical action between metal and medium, and corrosion resistance refers to the ability of stainless steel to resist the corrosion damage of medium. Therefore, when corrosion resistance is involved in material selection, the following points should be paid attention to.

The standard of corrosion resistance is artificially determined. It should be recognized and used, but it can not be bound by it. The specific standard of corrosion resistance should be determined according to the specific application requirements. At present, grade 10 standard is mostly used for the corrosion resistance of stainless steel. Which grade is selected as the corrosion resistance requirement should consider the characteristics of equipment and parts (thickness and size). Requirements for service life and product quality (such as impurities, color and purity). Generally speaking, level 1 ~ 3 standards can be selected for equipment, instruments and components requiring smooth mirror or precise size during use; For the equipment requiring close cooperation, long-term non leakage or limited service life, the components shall

It is very important to master the correct operation method, which is also beneficial for our later use. Next, let's understand what shall be prepared for the stainless steel pipe before welding:

1. In order to ensure the safety of the staff, it is critical for the staff to wear professional work clothes when welding products.

2. Check whether the grinding wheel is loose or whether it needs to be replaced before using the electric grinding tool.

3. The stainless steel pipe should be fastened with safety belt when working at high altitude, and the bracket should be safe and reliable.

Stainless steel pipe

4, when working in the air, if there are inflammable and explosive items below, should be prepared in advance to prevent spatter falling measures.

5. The electric welding wire shall not be connected with the equipment with induction coil, and the part connected with the welding clamp shall be placed reliably so as to avoid arc-hit steel pipe during operation.

1. The fresh water, fresh water for stainless steel welded pipe corrosion is mainly affected by the ph of water, water, oxygen and water to scale the influence of the bias.

2. The acidic water, acidic water refers to the immersion precipitation from ore and coal polluted natural water. Acidic water acidic water quality better than normal, this kind of water containing ferric sulfate for stainless steel welded pipe erosion effect is very big

3. Salt water, salt water for stainless steel welded pipe erosion are mostly caused by pitting corrosion of stainless steel welded pipe, the salinity of water in a certain level will lead to the breakage of the stainless steel welded pipe surface passivation membrane, resulting in corrosion of stainless steel welded pipe.

4. Soil, some people might say, how the soil corrosion were made of the stainless steel welded pipe? You want to know, soil surrounding atmosphere, and the rest of the ingredients can affect into the metal of the soil, the soil environment is unstable in the transformation of complex soil environment at any time.

Nitrate, nitric acid corrosion for any metal materials are very strong, nitric acid is mainly intergranular structure can be on the inside of the stainless steel welded pipe, high temperature and high concentration of nitric acid for stainless steel welded pipe erosion is very serious

6. Atmospheric corrosion. Atmospheric corrosion of stainless steel welded pipe corrosion in chloride and pollutant sources for stainless steel welded pipe erosion, the corrosion is very serious.

Strong acidic or alkaline environment tend to cause corrosion of stainless steel welded pipe, so in the process of use to stay away from these environments.

316 l stainless steel is often used in pulp and paper equipment heat exchanger, dyeing equipment, film processing equipment, pipelines, coastal areas with outside the building materials, and advanced a watch bracelet, watch case, etc. Water use equipment, chemical, dyestuff, papermaking, oxalic acid, fertilizer and other production equipment; Photography, food industry, coastal facilities, rope, CD rod, bolts and nuts.

316 l stainless steel mechanical properties:

Tensile strength (Mpa) 485 MIN yield strength (Mpa) 170 30 MIN MIN elongation (%) area of cut (%) of 40 MIN 7.98 g/cm3 density of 316 l stainless steel, hardness of HRB < 90 HV < 200 HBS < 187

The corrosion resistance of stainless steel depends on the alloy element content in the steel. Stainless Steel SUS316L density of 8.0 g/cm3 density Stainless Steel (Stainless Steel) refers to the weak corrosive medium such as air, steam, water resistance and acid, alkali, salt and other chemical etching Steel 316 l Stainless Steel tube corrosion medium, also called acid-proof Stainless Steel.

In practical application, often called the weak corrosive medium corrosion resistant steel stainless steel, and called the resistance to chemical corrosion medium steel acid-resistant steel. Due to the chemical composition on the difference between the two, the former does not necessarily medium resistance to chemical corrosion, while the latter are generally not rust.

Q235 is a common carbon structural steel-common plate, which represents a kind of steel material, Q represents the yield of this material, and the latter 235 refers to the yield value of this material, which is around 235 mpa. Due to the moderate carbon content, the comprehensive performance is better, the strength, plasticity and welding properties have been well matched, the most widely used.

Steel plate processing

1. Q235B steel plate CNC zero cutting machine if in special circumstances do not use acid welding oil, welding time should also pay attention to safety.

Q235B plate CNC zero cutting machine if there is a high voltage generator inside the circuit board, the need for proper insulation.

3 unloading Q235B plate CNC zero cutting cutting machine must be cut off before the total power supply, to prevent electric shock, so the power must remember.

4. Q235B plate CNC zero cutting machine to find out the power supply configuration and types of the circuit board, according to the need of inspection, the power supply or all the power supply.

5. The steel plate will be slightly deformed after overheating, so in order to prevent too much deformation, it is best to use the point-cut type.

Above is Q235 steel plate processing process should pay attention to the problem, hope to give you some help.

Rheological behavior of weathering steel plate during high temperature deformation



The scientific study of the mechanism and boron and forged weathering steel plate after quenching and tempering the characteristics of the carbon moisture content of aluminum alloy weathering steel plate has long been cast and pin damage detection plate.



Forged aluminum alloy weathering steel plate mechanism Fe2B phase and ferrite, metallographic tissue culture substrate, Fe2B phase circular arc pattern and network structure condensation.Weather resistant steel plate aluminum alloy 950?After hydrothermal treatment at 1100℃, quenching at 200℃ and partial fracture occurs, the alkali is converted to plate austenite.With the increase of heat treatment temperature, the breaking of Fe2B phase is obvious and there is a small amount of conventional plate austenite.Quenched and tempered forged aluminum alloy weathering steel plate of 55?60HRC, more than 10J/cm2 fracture toughness, after the strength of the dynamic fracture toughness more than 30MPa.M1/2.Under the damage standard of 120 mesh quartz sand wear-resistant materials, the wear resistance of high manganese aluminum alloy weathering steel plate is better than the above high chromium and low cast iron.According to the application type of sand and metal materials, the cooling rate of the external economic structure and the crystalline characteristics of the weathering steel plate harm the way.The improved crystallization rate of refrigeration can be refined in the mechanism, which is very ferrite, and the secondary dendrite arm interval is significantly reduced.Increase (Fe, Cr)3C martensite water content, reduce martensite size, resulting in improved physical properties.The thermal expansion of aluminum alloy in the dynamic work hardening weathering steel plate, and the deformation temperature and strain rate are obviously harmful to the rheological in-situ stress. With the rise of temperature, the deformation rheological in-situ

Among many metal materials, the weldability of carbon steel plates is relatively good, and the welding parameters range is wide. Generally, no special measures are required in the usual thickness range (0.5-3.0mm). The unidirectional power frequency AC power supply is adopted, and the welding cycle is simple. Satisfactory welding results can be achieved.

So what kind of spot welding machine can be used to weld low-carbon steel to weld high-quality product workpieces? What are the precautions for carbon steel welding? Today, Sunar welding engineers will briefly introduce the relevant knowledge of carbon steel welding.

Precautions for welding of carbon steel plates:

1. Due to the good welding performance of carbon steel plates, when the plates are not thick and the welding requirements are not too high, the welding requirements can be achieved by choosing an AC spot welding machine.

2. If the equipment cost permits, try to use an intermediate frequency inverter spot welder to spot weld low-carbon steel plates, the welding effect will be better, and the nugget and welding points will be more perfect.

3. Carbon steel plates include cold-rolled steel plates and hot-rolled steel plates. The cold-rolled steel plates do not need to be cleaned before welding. The hot-rolled steel plates must be cleaned of impurities such as oxide layer, rust, and oil stains on the surface.

4. If the capacity of the spot welding machine used permits, Sunar still recommends the use of hard standard welding to reduce the influence of heat diffusion on the product and at the same time reduce product deformation.

5. For the electrode tip material, we recommend to use electrode materials with medium conductivity and medium strength, such as Cr-Cu or Cr-Zr-Cu alloy electrodes.

6. When the surface cleaning quality is poor or the stamping accuracy is poor and the rigidity is large, consider the use of amplitude-modulated current measures to solve the splash problem.

The above has explained t

Wear resistant plate due to high hardness, double layer characteristics, so when machining should pay more attention to.For example, the cutting of wear-resistant plate can be used for plasma cutting, water knife, electric spark, carbon arc, grinding wheel saw to cut the large area of laminated steel plate into the desired shape.

The ideal method is to cut with an air or inert gas plasma arc. The recommended method is to start cutting from the back of the alloy.Carbon arc cutting should start from one side of the substrate.If a saw blade is used, it can only be cut in a straight line, and a silicon carbide saw blade is needed.

Wear plate can be cold processing molding, according to the need to bend into the required shape, or arc or circle.Concave forming, alloy cracks due to internal stress will be closed;Convex forming, the crack will become larger cracking, which is normal site.If the crack is too large, use the appropriate electrode to repair.Curl into a tube with the recommended small bending radius.

The large hole on the wear plate can be cut by plasma. The small hole is recommended to use water knife, electric spark, etc.The countersunk head holes for bolt assembly can be machined by a special process.The base metal of the large-area composite steel plate is the steel plate with good weldable performance. When two steel plates are spliced together, the back base metal can be welded together first, and then the front surfacing layer can be filled up with the corresponding surfacing electrode.Wear-resistant steel plates can also be welded to other steel structures.

The bolt can be welded to the base metal of the steel plate and then connected with other workpieces by welding method, or it can be connected with other workpieces through bolts by opening holes in the wear-resisting steel plate.Wear plate indicates that no processing, if need processing, can only be grinding, other conventional methods are not applicable.Wear - resistant plate is not suitable f