Stainless steel band

stainless steel strip and other materials, like the physical properties including the following three aspects: melting point than the electromagnetic properties of the heat capacity, thermal conductivity and thermal properties of linear expansion coefficient, electrical resistivity, conductivity and permeability, as well as Young's modulus mechanical properties of rigidity coefficient. These properties are generally considered to be the inherent characteristics of the stainless steel material, but will also be affected, such as temperature, degree of processing and the magnetic field strength and the like. Often compared to stainless steel and iron, low thermal conductivity, resistance, and the linear expansion coefficient and permeability properties depending on the crystal structure of the stainless steel itself varies.

Stainless steel cold

There are basically three kinds of cold working process, namely cold drawing process, cold rolling, cold - drawing a joint process. Most foreign stainless steel plate tube of cold-rolled cold - drawing combined process, and mainly cold rolled, cold drawn, supplemented by processing methods.
     Modern cold rolling mill can achieve greatly reduced diameter and greatly reduced the amount of wall thickness, the deformation of 80% complete at the cold rolling mill. Fixed using cold wall, combined with cold call to change the specifications and control diameter, to meet the different varieties and specifications.
     Cold rolling - drawing combined production process advantages are: good quality steel, high precision cold-rolled steel pipe wall thickness and surface quality, cold technology to ensure the accuracy of pipe diameter; cold period is short, reduce intermediate degreasing, heat treatment, necking, straightening and other processes, saving energy, reducing metal consumption; shortage of large-sized tubes can be used raw material to produce small-diameter steel pipe, simplifying the type of raw material specifications.
     Currently, cold-rolled and cold drawn technology and equipment level has been greatly developed world. Cold rolling mill forward speed, long stroke, ring pass, high-precision direction, this mill is characterized by:
     * Use the inertia force and inertia torque balance mechanism vertical mill roundtrips to improve;
     · Using circular hole, rolling mill block length is shorter than the stroke length of 70% to improve the uniformity of rolling deformation, increase the amount of feed;
     · Adopt a long tube, pipe material shortage length can be increased from 12 to 15 meters, can produce long steel pipe, increase mill utilization, effective utilization coefficient of rolling up to 80%;
     · Adopt and best parabolic curved mandrel hole, metal deformation reasonable, tool and die life is high.

304 stainless steel corrosion

Corrosion resistance of 304 stainless steel mainly depends on its alloy composition (chromium, nickel, titanium, silicon, aluminum, manganese, etc.) and internal organizational structure, play a major role in the chromium.
Chromium has a high chemical stability, can form a passive film on the steel surface, the metal with the outside world to isolate and protect steel from oxidation and increase the corrosion resistance of steel. After the destruction of the passive film, corrosion resistance on the decline.
Can bear a variety of acid etching, such as: oxalic acid, sulfuric acid - iron sulfate, nitrate, nitric acid - hydrofluoric acid, sulfuric acid - copper sulfate, phosphoric acid, formic acid, acetic acid, etc.,
Widely used: chemical, food, pharmaceutical, paper, oil, atomic energy, construction, kitchen utensils, cutlery, vehicles, household appliances. 304 stainless steel plate surface appearance as well as the possibility of using diverse good corrosion resistance, long-term durability than ordinary steel. 304 stainless steel high strength, and therefore the possibility of the use of thin, high temperature oxidation and strength, and therefore resistant to fire, room temperature processing, which is easy to plastic processing
Because the surface treatment is not necessary, so simple, easy maintenance, clean, high-quality finish, good weldability.

Stainless steel mesh

Stainless steel mesh is made of stainless steel as raw material, with the broad language to describe the words: refers to the use of stainless steel wire rod or plate such as stainless steel production from the processing of mesh products.
   There are stainless steel coil in more detail in the following category:
   1, according to the materials can be divided into: SUS302, SUS304, SUS316, SUS304L, SUS316L, SUS310, SUS310s, SUS430 and other grades.
   2, from the production process can be divided into: weaving, Welding, stretching, punching, etc; which can be woven into plain weave, twill weave, Dutch plain weave, twill weave Netherlands, reverse Dutch weaving and other crafts .
   3, according to the different forms of technology and materials can be divided into: stainless steel wire square mesh, stainless steel I-type mesh, stainless steel welded wire mesh, stainless steel mesh, stainless steel perforated metal mesh and other varieties.
   Uses: Widely used in stainless steel mesh screen filter and protective decorative, scope throughout the mining, petroleum, chemical, food, medicine, machinery manufacturing, construction decoration, electronics, aerospace and other industries.
   Features:
   1, room temperature processing, plastic processing that is easy to diversify the possibility of using a stainless steel mesh;
   2, finish, surface treatment is not necessary, convenient and simple to maintain.
   3, high temperature oxidation, 304 stainless steel mesh withstand temperatures of 800 degrees Celsius, 310S stainless steel mesh withstand temperatures up to 1150 degrees Celsius;
   4, good acid and alkali resistance, corrosion performance;
   5, high strength, tensile, toughness and wear resistance and durability;

Stainless tightness

How to maintain the purity of the protective gas furnace is a key issue. In this regard, stainless steel magnetic sealing, and it will not happen as electric furnace material contamination protective atmosphere, providing a more pristine environment of space. Additionally, vertical furnace strip entrance are located lowermost portion of the furnace, the furnace pressure is stable, as compared with a horizontal furnace, air enters the danger is much smaller. However Importers sealed box furnace for bright annealing, the strip conveying section, the dancer roller and the guide roller roof box should ensure a few parts per million (ppM level) sealing requirements, so that oxygen, water vapor can not enter the shielding gas can not escape.
Vertical bright annealing furnace construction should pay attention to issues related to
In the long-term high temperature will creep elongation. Structurally the muffle cover hanging on the roof, in a suspended state, cover the lower part of the water ring seal, not fixed, allowing a certain amount of creep. Creep accumulated to a certain amount, remove seal, with a special plasma cutter to cut away along the lower section of the hood muffle. About half cut once. Cutting operating requirements are relatively high. Its special equipment, operating space and structure, operational reliability should pay full attention.

The purpose of the process of stainless steel bright annealing

430 stainless steel magnetic bright annealing furnace is mainly used to finished product heat in the atmosphere of the processing of stainless steel. When using the performance requirements are not at the same time, on the microstructure of bright annealing after the requirements are different, the process of bright heat treatment are also different.
Heat treatment process of typical 430 stainless steel suppliers magnetic is a solid solution treatment. In the heating process of the carbide dissolve in austenite, heated to 1050 ~ 1150 ℃, the appropriate holding a short period of time, the carbide all dissolved in austenite, and then rapidly cooled to 350 ℃, obtain supersaturated solid solution is uniform one-way austenite. The heat treatment process is the key to rapid cooling, cooling rate reached 55 ℃ /s, fast through the carbide solid solution after precipitation temperature region (550 ～ 850 ℃). Holding time should be as short as possible, otherwise the coarse grain, effects of surface finish.

The scope of application of iron 1.4016 steel 2R and physical phenomena
Iron 1.4016 steel 2R in the heating process the carbide dissolve into austenite, heated to 1050 to 1150 DEG C, the effect of a short period of time, the carbide all dissolved in austenite, and then rapidly cooled to 350 DEG C, to obtain supersaturated solid solution is uniform one-way austenitic organization. The heat treatment process is the key to rapid cooling, the cooling rate reaches 55 DEG C requirements of /s, iron 1.4016 steel 2R fast through the carbide solid solution after precipitation temperature zone (550 to 850 DEG C). Holding time should be as short as possible, otherwise the coarse grain, surface finish.

Stainless steel performance specifications

Hot plate series: materials are 310S (0Cr25Ni20 or 1Cr25Ni20Si2), 309S (0Cr23Ni13 or 1Cr20Ni14Si2), 2205 (S31803) duplex stainless steel, 253MA (S31805) heat-resistant steel, thickness 0.4mm-60.0mm
Chemical board series: materials are 316L (00Cr17Ni12Mo2 American Standard and 00Cr17Ni14Mo2 GB), 316Ti, 321 (1Cr18Ni9Ti or 0Cr18Ni10Ti), 304L (00Cr18Ni9), 304 (0Cr18Ni9), 304J1 (304 copper material), 202 (1Cr18Mn8Ni5N), 201 (1Cr17Mn6Ni5N), etc., the thickness of 0.4mm-60.0mm plate series: Specifications 3.0mm-30.0mm * 1500/1800 * 2000 * 6000 or 6000 or more. Normal tolerances or small negative balance campaign materials, 3.0mm-14.0mm length can be cold-rolled sheet series: Specifications 0.4-6.0mm * 1219/1000 * 1500 * 2438/2000 / not length, length can be set to open 304 is a general purpose of stainless steel plate, it is widely used to produce good overall performance requirements (corrosion resistance and formability) of equipment and parts.
301 stainless steel suppliers in the deformation showing a significant hardening, are used for a variety of applications require a higher intensity.
302 stainless steel is essentially a higher carbon content of 304 stainless steel variant, it may be obtained by cold-rolled high strength.
302B is a high silicon content of stainless steel, it has a high temperature oxidation resistance.
303 and 303Se are cutting stainless steel containing sulfur and selenium, the main requirements for cutting and table Guanghao high occasions. 303Se also necessary for the production of stainless steel hot forging of parts, because in such conditions, this steel has good hot workability.
304L is a low-carbon 304 stainless steel variant, the need for welding applications. Lower carbon content makes it close to the weld heat affected zone to minimize carbide precipitation, and carbide precipitation may lead to intergranular corrosion of stainless steel in some environments (welding erosion).
304N is a nitrogen-containing stainless steel, add nitrogen to increase the strength of steel.
305 and 384 stainless steel with high nickel, the hardening rate is low, suitable for cold forming requires a variety of occasions.

Galvanized steel oxidation process introduced

Galvanized 409 stainless steel plate oxidation process introduced
(1) black handle. By some special treatment, as galvanized steel 1Cr13,3Cr13,4Cr13 on black nickel and zinc plating layer blackened.
     ① black nickel plating solution composition and soil conditions Arts
     Molybdate press [(NH4) 6Mo7O24.4H20] 30 ~ 40g / L
     Nickel sulfate (NiS04.7H2O) 120 ~ 150g / L
     Boric acid (H3BO4) 20 ~ 25g / L
     a pH value of 4.5 5.5
     20 to 25 ℃ temperature
     Cathode current density 0.15 ~ 0.3A / dm2
     15 hours a 20min
     ② black zinc coating solution composition and process conditions
     Molybdate press [(NH4) 6Mo7O24.4H20] 300g / L
     Aqueous ammonia (NH3 · H2O) (d = 0.89) 600mL / L
     Temperature 30 ~ 40 ℃
     Time 10min
     (2) Galvanized - black nickel plating process. Electrolytic degreasing → washing → weak corrosive (sulfuric acid 110mL / L, thiourea 10g / L, wash clean right amount) → washing → galvanized [NH4Cl220 ~ 280g / L, ZnCl230 ~ 35g / L, H3BO325 ~ 30g / L, polyethylene diol 1 ~ 2g / L, thiourea 1 ~ 2g / L, detergent 0.5 ~ 1mL / L, pH5.6 ~ 6.0, temperature 10 ~ 35 ℃, the cathode current density (Dk) 1 ~ 1.5A / dm2, the time 30s] → washing → retreat zinc (ZnCl250g / L, HCl50mL / L, room temperature, and the time to do back up) → washing → weak corrosion (ZnCl250g / L, HCl50mL / L, room temperature, and the time to do back up) → washing → galvanized
     (Time 5min) → → washing → black nickel plated closed treatment (CrO32.5 ~ 5g / L, pH1.5 ~ 5, temperature 10 ~ 30 ℃, time 10 ~ 20s) → washing → dry (less than 500 ℃)
     (3) galvanized black treatment process. Pre-galvanized and pre-treatment to black nickel plating process → galvanizing same (time 1.0 ~ 15min) → washing → → washing → black zinc coating and drying.

Stainless steel sheet during the drawing when what features

Stainless steel products for its exquisite appearance, excellent corrosion resistance, high temperature oxidation resistance and high temperature strength and drew people of all ages, more and more widely used for decoration, light industry, civilian hardware, kitchen equipment and utensils, etc. . Due to the high quality requirements of the appearance of these products in the whole process of the product, to ensure that the product is not high surface brightness scratches and abrasions very difficult indeed, especially since 304 stainless steel sheet sheet drawing characteristics brought Die Selection , heat treatment, machining and process lubrication problems directly affecting product quality gold, production, costs and die life.

     Features stainless steel sheet drawing

     Due to the high yield point of stainless steel 304ba, high hardness, work hardening effect is remarkable, stainless steel sheet were drawing the following features:
     1) due to poor thermal conductivity than ordinary low-carbon steel, resulting in deformation force required;
     2) stainless steel sheet drawing, the severe plastic deformation hardening, easy to wrinkle when drawing sheet, full BHF want greater;
     3) sheet metal bending in the rebound and reverse pull furrow mold caused by bending at the corner, and usually forms a depression in the side wall of distortion product makes high dimensional accuracy and shape requirements of the product to achieve the required increase in plastic surgery procedures.
     4) stainless steel sheet bonded tumor phenomenon drawing process prone.
     From the microscopic point of view, the key panel material rough mold surfaces are uneven, due to the process of drawing BHF larger load raised by the local unit to withstand a lot of pressure parts; because between the sheet and the mold to produce relative motion and the plastic deformation of sheet metal production of heat, making the lubricating film viscosity decreases, lower intensity; protruding parts of the sheet in a high pressure, high temperature instantaneously by shearing motion, the lubricant film rupture, sheet metal in direct contact with the mold, sheet metal parts to be scraped off the mold raised bumps become part of people die in front of the debris pile protruding parts, such as the temperature is high enough so that the pieces soften, melt, dry welding in the mold to form an adhesive tumor. Bond and form a tumor is difficult to come off, and the more the bigger stick, causing deep drawing steel sheet products severe scratches left on the surface. In addition, the drawing speed, sheet deformed child size also plays an important role on the bond neoplasia. How to avoid drawing die bonding tumor formation, improve the surface quality of drawing parts are stainless steel sheet drawing technical problems lies.

     2 solutions

     Deep drawing steel sheet bonding occurs during tumor has been plagued by production site, a great deal of trouble to producers, but due to the bonding neoplasia and other issues related to tribology, influenced by many factors. Currently, we can only propose measures from different angles to prevent tumor formation and reduce adhesion.

     2.1 working part mold material selection and heat treatment

     For bond tumor problem, choose a stainless steel mold material Chak relations, two points should be combined according to the pro stainless steel sheet metal and mold material: Choose one anti-adhesion strength, and second mold material wear and friction reduction. In general, the metal lattice type, lattice pitch, electron density, electrochemical properties interlinked metal, which attract each other, dissolving ability, easy to adhere together, the results of the friction coefficient becomes large. Cr, Ni and Fe miscibility big, so when using steel deep drawing, bonding tumors more susceptible to the phenomenon. Practice has proved that: use aluminum bronze, aluminum bronze hard sticking better; using Steel bonded tungsten carbide manufacturing die than raise with Cr12Mov tufftride manufacturing die life several times, and non-stick mode; if using code 3054 alloy cast iron, just mold surface flame hardening, the mold surface does not appear bond tumor. Also in vulnerable parts of the mold can be used carbide inserts, it has excellent compression performance, superior wear resistance and long-lasting love of the surface roughness and dimensional control. However, due to the price, the production used less.
 
     Surface processing mold work portion 2.2

     Stainless steel drawing die surface quality requirements are high. Low surface roughness may serve to improve the anti-friction and anti-adhesion effect so. After drawing die during the grinding process, the more important is to eliminate machining marks. In the mold is often overlooked grinding and polishing processes. It should be noted. Throughout the mold process, polishing workload should account for one third, because the appearance of quality stainless steel products depends largely on the mold polishing techniques. Reduce mold surface roughness, a corresponding reduction in the number of grinding mold, mold life correspondingly improved.
     If the mold surface polishing enough, coupled with deep drawing steel sheet bonded easily cause tumor characteristics, thus drawing out of the product scratches serious. And that the scratches on the product with polished to solve time-consuming and reach results. Therefore, we should step up and down in the mold polishing great effort, only the mold surface machining accuracy is improved in order to reduce scratches, mold repair mold life can be greatly improved. In recent years, there have been a variety of new techniques of polishing and polishing tools, the development of ultrasound, electrolytic polishing, abrasive blasting, honing extrusion and other new technology, new equipment. According to information on CrWMo, 3Cr12W8V, Cr12 mold test three materials studied electrochemical polishing, polishing prove that only 5-10 minutes from the mold cavity surface roughness of the original Ra3.2-Ra1.6 down to Ra0.4-RaO.2 basis. While by electrochemical polishing may improve the surface hardness to improve wear resistance. Again, ultrasonic polishing machine can be used by soft nitriding treatment cavity fine polishing, it is easy to avoid the disadvantages of manual polishing damage nitride film. For new polishing techniques we should take active steps to use and summary.
     Stainless steel drawing die surface quality requirements are high. Low surface roughness may serve to improve the anti-friction and anti-adhesion effect so. After drawing die during the grinding process, the more important is to eliminate machining marks. In the mold is often overlooked grinding and polishing processes. It should be noted. Throughout the mold process, polishing workload should account for one third, because the appearance of quality stainless steel products depends largely on the mold polishing techniques. Reduce mold surface roughness, a corresponding reduction in the number of grinding mold, mold life correspondingly improved.
     If the mold surface polishing enough, coupled with deep drawing steel sheet bonded easily cause tumor characteristics, thus drawing out of the product scratches serious. And that the scratches on the product with polished to solve time-consuming and reach results. Therefore, we should step up and down in the mold polishing great effort, only the mold surface machining accuracy is improved in order to reduce scratches, mold repair mold life can be greatly improved. In recent years, there have been a variety of new techniques of polishing and polishing tools, the development of ultrasound, electrolytic polishing, abrasive blasting, honing extrusion and other new technology, new equipment. According to information on CrWMo, 3Cr12W8V, Cr12 mold test three materials studied electrochemical polishing, polishing prove that only 5-10 minutes from the mold cavity surface roughness of the original Ra3.2-Ra1.6 down to Ra0.4-RaO.2 basis. While by electrochemical polishing may improve the surface hardness to improve wear resistance. Again, ultrasonic polishing machine can be used by soft nitriding treatment cavity fine polishing, it is easy to avoid the disadvantages of manual polishing damage nitride film. For new polishing techniques we should take active steps to use and summary.