Application of stainless steel
Stainless steel not only has good corrosion resistance, but also has a variety of characteristics such as good appearance, and the application of stainless steel is becoming more and more widespread. The following table shows simple examples of applications of stainless steel.
| Industry | Main Usage Examples |
|---|---|
| For Automobiles |
Exterior Components Internal parts |
| FLATWARE (a kind of utensil) |
SPOON, FORK – export or domestic sales Knives-export or domestic sales |
| HOLLOWWARE tableware (two kinds of utensils) |
DRAWING (general stretching) – stretching ratio less than 1.5 PRESS (stamping) SPINNING |
| Kitchen equipment |
Washing tank (SINK) general stretching material (high surface requirements) Gas stove – high surface requirements Refrigerator (freezer liner) |
| Electrical appliances |
Washer, dryer Microwave Oven Electronic components (non-magnetic) |
| For steel pipes |
Decorative tubes Constructed tubes (industrial) For drainage pipe |
| Construction Materials |
MIRROR (mirror material) Re-grinding Elevator Building interior and exterior decorative materials elevator Windows, door materials |
| Chemical equipment |
Heat Exchangers Boilers, tanks Chemical industry furnace Chemical equipment components |
| General Purpose |
REROLL (for re-rolling steel) For high hardness For processing plants For market circulation Special Purpose |
| Transportation equipment |
Container Railroad cars |
Stainless steel in the construction industry
In recent years, the application of stainless steel as a building material is becoming increasingly widespread. The use of increasingly widespread for a variety of reasons, including a better understanding of the material, attempts to update certain designs, envisage the production of a durable and maintenance-free structural materials.
In the early days, the use of stainless steel for construction was limited to certain occasions, that is, in the past, it was not considered appropriate material for the occasion architects are seeking a new material with a special role. In fact, many such occasions, stainless steel has been used for a long time and its effect has been after a long period of continuous washout effect on stainless steel, so that manufacturers believe that stainless steel materials for outdoor occasions even in highly corrosive gas conditions are not corrosive.
In recent years, the walls of swimming pools have been made of stainless steel. The main material used for a long time concrete needs to be repaired and painted every year, especially in the northern region . Built with carbon steel and coated swimming pools also need a large area of scrubbing and painting every year, both of which have increased the pool a considerable amount of use expenditure. When the pool is made of stainless steel (304 type, 2B finish) to do the sidewalls, scrubbing is very simple, just water and soap can be quickly washed. Nowadays, swimming pools often use stainless steel tank walls and mixed pressed earth pool bottom, the pool bottom with concrete is mainly for non-slip.
The walls of some buildings with 304 type, 8 grade mirror polished stainless steel for materials. Interconnected stainless steel panels are polished and coloring polished so that the walls have a consistent color fade and reflectivity. To prevent grease, large areas of stainless steel panels are installed in a thick sandwich consisting of galvanized and compressed panels. Polished stainless steel plate with epoxy resin as a binder and galvanized steel plate connection fixed.
By dry stainless steel can get very soft properties, making it right possible to use for roof covering material. It is because this material is easy to form, durable and beautiful, so many architects choose stainless steel not only simply as a protective layer, but as part of the overall design.
Some buildings (indoor skating rink pipe) with stainless steel materials to build a permanent flat overlap layer of the roof, not only make the building from the design point of view beautiful and elegant, but also because of the reflective effect of the stainless steel surface, so that the indoor skating season can be extended and rabbits to bear unreasonable investment.
For some special structures, often due to the application of stainless steel so that many difficult problems are solved. For example, there is a car garage, the design requires parking garage for parked cars not only to have a protective role and good ventilation of the exhaust gas; but also to make a certain degree of sunlight into the garage, the choice of materials both durable and maintenance-free. In order to meet the above requirements, the designer chose 6*10in (15*25cm) 201 stainless steel grating, the grating is fixed on the vertical column, so that the inside and outside staggered resulting in overlapping layout. In order to enhance the architectural design effect, the interlaced outer lattice plate with a floating surface finish, the outer rows of column lattice plate with a common 2B finish, all inside the lattice plate are 2D finish. This interlocking and changing pattern gives the garage a vivid appearance.
For the roof structure of a building, its service life and appearance should be given equal importance. In the airport’s restaurant, the exhaust fans are covered with stainless steel panels to make the roof aesthetically pleasing. Special emphasis was also placed on the non-reflective nature of the material when selecting the covering material. The village material selected is type 304 stainless steel, coarse polish, low reflectivity, and 6 grade finish. For the choice of light put degree to pay special attention to especially due to the emission of glare, preventing the pilot’s vision when landing at their destination.
Office hall inside and outside the building to the structure are used in stainless steel materials. Its architectural measures using stainless steel as a curtain wall. Building entrance columns are wrapped in stainless steel panels, all the windows of the building front purification device are also covered with stainless steel.
Office building lounge above the no-flower panels are composed of stainless steel panels with relief. The use of male and female die punching stainless steel sheet on the relief part.
Stainless steel not only has a long service life, but also is a good material for the production of captive convex to the structure, which can enhance the beauty of the building shape, so often the main symbol of the square.
Stainless steel as the main material used for outdoor architecture is another example of the famous arch bridge that stands on the river.
Stainless steel material can be chosen at will. It has a variety of different strength-to-weight ratio to suit the requirements of various types of building structures. In addition, the different grades of surface finish provide a range of options to meet the practical needs of different architectural facilities. The bold ideas of architects will make stainless steel in the construction industry is increasingly widely used.
Stainless steel on marine installations
Different types of stainless steel are being used increasingly widely and successfully in a variety of different marine environments. It is important to note that stainless steels in seawater require complex corrosion protection engineering techniques and significant investment to be corrosion free in the long term. Austenitic and martensitic stainless steels have long been used in superheater piping and turbine blades on marine power plants. In these devices to maintain a low chloride content is not easy, because the application of marine power plant technology and the general power generation plant does not differ from the basic principles. Stainless steel is also being used for large-capacity chemical vessels on ocean-going merchant ships, whose use is in some respects very different from the conditions of use in land-based chemical plants.
Most stainless steel grades can be applied under marine conditions to obtain satisfactory results, but different grades are sensitive to stress corrosion cracking performance. Martensitic steel represented by type 410 and ferritic steel represented by type 430 will rust within a few months under marine conditions. This uniform rusting can be removed by mechanical polishing. The more popular stainless steel is austenitic stainless steel because of its high resistance to rusting (with the exception of cracking due to stress corrosion). Austenitic stainless steel will also blacken as it migrates over time. This blackening can also be removed by polishing if for aesthetic or other reasons. Stainless steel rarely rusts uniformly in seawater, so it is not a concern in practice.
Thrusters The thrusters on ocean tugs and other vessels can be made of cast stainless steel CF-8 (equivalent to dry type 304 stainless steel). When the ship is not sailing, from the thruster spindle through the bearing to the hull, forming a conductive metal circuit. The equivalent composition of 410 type stainless steel casting thruster is often phi selection, and in other areas are widely used, such as for icebreakers.
The development of stainless steel technology in recent times, has begun to use complex austenitic-ferritic stainless steel 20Cr-8Ni-3.5Mo to cast large propellers (weighing up to 3000kg) on ocean-going vessels.
Often in the port work of the ship, especially likely to encounter the sea logs or other floating bodies and accelerate the damage to the propeller. Therefore, the use of austenitic stainless steel thruster can be repaired by straightening or welding, which is a matter of importance in the selection of materials.
Pumps have long been observed centrifugal pumps in seawater working conditions, such as the use of stainless steel components, it can show a certain degree of reliability. In keeping the flow of seawater, the use of CF-8M casting stainless steel impeller (its composition is equivalent to type 316 stainless steel) as well as with type 316 stainless steel for the main shaft, can not be any problem. When the pump stops working, crevice corrosion and pitting corrosion is likely to become a serious problem. But if you come to use the more active and rust-prone cast iron manufacturing a wall thickness of a fairly large pump box, cast iron in downtime can play a cathodic protection role. When the pump work, cast iron box cathodic protection must be able to polarize under the stainless steel, but the flow of water to maintain the role of cathodic protection. In addition, long-term work of the pump may be due to alternate use, both when seawater replaced with fresh water and play a protective role.
Bulk container Stainless steel has been used as a bulk bag container in freight, to carry liquefied natural gas (LNG), chemicals, beverages, etc. Containers holding LNG in freight are customarily made of type 304L stainless steel, the purpose of which is not to resist corrosion but to take into account the mechanical properties in the low-temperature state.
For the container of marine chemicals, the purpose of using stainless steel is mainly to consider its corrosion resistance, which is different from the storage and transportation of chemicals on land. If the ship belongs to the general unscheduled cargo ships, the container carrying chemical products can also transport any items, from acetic acid, bad slurry to xylene. Generally, type 316L stainless steel is used for valves, cargo pumps, pipe was, heating coils and the vessel itself. The container can be composed of stainless steel or carbon steel wrapped on a layer of 0.06 to 0.08in (1.5-2.0mm) made of stainless steel plate. Before use, the plate must be carefully inspected for defects and thoroughly cleaned and passivated.
Experiments have shown that vessels containing chemicals are allowed to be rinsed with sea water, but must be rinsed with fresh water soon afterwards. For any stainless steel heating device inside the vessel, do not start until the chlorine has been thoroughly flushed out to prevent stress corrosion cracking. Chemical container design, should not be considered to hold seawater because it will lead to the risk of crevice corrosion. If the design program must be used to hold seawater, then you must consider taking cathodic protection system to control the development of crevice corrosion. In this case, the stainless steel vessel may produce difficult to remove the limestone deposits, which is a problem worthy of attention.
Heat exchangers Forced water circulation system coolers and power station steam condensers have been widely used austenitic stainless steel piping, the latter inlet is not suitable for copper alloy material because of the high degree of contamination. The more popular good material is type 316 stainless steel. In coastal and harbor areas, a large number of foreign clumps and silt into the condenser piping, especially prone to serious obstacles, this situation must take measures to exclude. A reasonable measure is the use of rubber balls circulating through the pipe, as the rubber balls can produce a squeezing effect thus cleaning up the pipe wall. When the flow rate of seawater is about 1m / S, it can prevent marine organic debris is inhaled, thus protecting the condenser pipeline from pitting corrosion. Unlike other non-ferrous alloys, the use of stainless steel condenser piping is not limited by the maximum flow rate, but with the economic effect of the entire pumping unit.
O-ring O-ring tandem electrical connectors and O-ring positioning devices are widely used 304 type and 316 type stainless steel manufacturing, especially in marine and military engineering. The use of the above materials can be used to obtain satisfactory results. o-ring seal can be cathodic protection through the hull, aluminum frame or other factors. Without cathodic protection, the O-ring can quickly (in some cases within a few weeks) develop gap rot candles and lead to serious failure.