Stainless steel is one of the commonnest steeliness material of the bring into contact with in meter job, understand stainless steel knowledge, the control with conduce to help appearance person better appearance type selecting and use.
Stainless steel (Stainless Steel) it is not to become rusty the abbreviation of acid-proof steel, be able to bear or endure air, vapour, water corrode medium infirmly or have do not become rusty sexual steel is planted call stainless steel; And will be able to bear or endure chemistry corrodes medium (the chemical dip corrode such as acerbity, alkaline, salt) cankerous steel is planted call acid-proof steel.
Stainless steel points to be able to bear or endure the air, vapour, water steel that corrodes medium and acid, alkaline, salt to wait for medium of sex of chemical dip corrode to corrode infirmly, say not to become rusty again acid-proof steel. In applying actually, the steel that often will be able to bear or endure to corrode medium infirmly calls stainless steel, and will be able to bear or endure the steel that chemical medium corrodes calls acid-proof steel. As a result of both the difference on chemical composition, former and differ be able to bear or endure surely chemical medium is corroded, and latter all is had commonly do not become rusty quality. Of stainless steel be able to bear or endure corrode sex depends on the alloying element that contains in steel.
Common classification
Organize cent to be by metallographic normally:
Normally, according to metallographic organization, be average stainless steel branch 3 kinds of: ? of Ao of of sour of Su of T of frame of Sun of suddenly of canister of salty Xiao of Xing of ⒙ of frame of Sun of suddenly of canister of Xiao of dimple of of ⑻ of frame of Sun of suddenly of canister of rate salty Xiao is disconcerted peptide of bamboo-plaited basket or suitcase of Cheng of ㄐ of Xin of eulogy of of rare of ∩ of of of Jian Mi scull Juan Song of of Chang of handleless cup of health model .
1, austenite stainless steel.
Matrix is organized with the austenite of structure of crystal of face heart cubic metre (CY photograph) give priority to, without magnetism, basically make through cold working its aggrandizement (bring about certain magnetism possibly) stainless steel. American steely association with the 200 digital designation with 300 series, like 304.
2, ferrite stainless steel.
Matrix is organized with the ferrite of structure of crystal of body heart cubic metre ((A photograph) give priority to, have magnetism, cannot pass heat treatment sclerosis commonly, but cold working can make his slight the stainless steel of aggrandizement. American steely association with 430 and 446 for designation.
3, martensite stainless steel.
Matrix is organized for martensite (body heart cubic metre or cubic) , have magnetism, can adjust its through heat treatment the stainless steel of mechanical function. American steely association with 410, 420 and 440 numbers are indicative. Martensite has austenite organization below high temperature, should come with proper speed refrigeration when room temperature, austenite organization can transform for martensite (namely hard) of temper by dipping in water.
4, austenite one ferrite (double photograph) model stainless steel.
Matrix holds austenite and ferrite two-phase structure concurrently, among them the content of less photograph matrix is more than commonly 15% , have magnetism, can make through cold working the stainless steel of its aggrandizement, the 329 double photograph stainless steel that are a model. Compare with austenite stainless steel, intensity of double photograph steel is high, be corroded between brilliant and be able to bear or endure chloride stress is corroded reach spot corrosion ability to all have rise apparently.
5, precipitation sclerosis stainless steel.
Matrix is austenite or martensite organization, can process the stainless steel that makes its sclerotic through precipitation sclerosis. American steely association the number with 600 series is indicative, like 630, namely 17-4PH.
Generally speaking, outside eliminating alloy, the corrosion resistance of austenite stainless steel is more exceedingly good, be in caustic in inferior environment, can use ferrite stainless steel, in spending caustic environment gently, if ask material has high strenth or tall hardness, can use martensite stainless steel and precipitation sclerosis stainless steel.
Character and utility
Exterior craft
Ply is divisional
1, because steelworks machinery is in rolling process, roller be heated appears subtle be out of shape, the bat ply that brings about make friends to come out appears deviation, general intermediate thick both sides is thin. When measuring bat thickness national regulation should measure board head intermediate place.
2, the account that tolerancepublic errand produces is a basis the market and client demand, is general component big common difference and: of little common difference? ?
What kind of stainless steel rusts not easily?
The main factor with influence rustily stainless steel has at 3 o'clock:
1, of alloying element content.
Popularly says chromic content rusted not easily in 10.5% steel. The content of chromic nickel jumps over tall anti-corrosive properties to had been jumped over, the content that like 304 material qualitative nickel wants is in 8-10% , chromic content achieves 18-20% , such stainless steel is won't rusty usually.
2, the corrosion resistance that produces the smelt craft of the enterprise to also can affect stainless steel.
Smelt technology good, equipment no matter the big stainless steel plant with advanced, advanced technology is the control in alloying element, the control of temperature of refrigeration of the purify of foreign matter, billet can get assuring, because this product is simple quantity stability is reliable, immanent quality is good, rust not easily. Conversely a few small steelworks device are backward, craft is backward, in smelt process, foreign matter cannot purify, product hard to avoid of production will be rusty.
3, external environment, climate is dry breezy environment rusts not easily.
And air humidity is big, weather of successive overcast and rainy, or the environmental area with great acid-base value is contained to become rusty with respect to Yi Sheng in air. 304 material qualitative stainless steel, if circumjacent environment is too poor,also be can rusty.
How should be stainless steel occurrence rusty spot handled?
1, chemical method
Cream with pickling or sparge assists his new passivation forms rustily place oxidation chromic film makes its restore afresh anti-corrosive ability, after pickling, for purify all contaminant are mixed acerbity hangover, it is very important to undertake be rinsinged appropriately with clear water. Polishing device is used after everything is handled new polish, use polishing dried meat to close can. What ministry of play a game of chess has slight rusty spot is usable also 1: Mixed liquor of the benzine of 1, engine oil obliterates with clean dishcloth rusty spot can.
2, mechanical method
Gush is arenaceous clear, with glass or particle of pottery and porcelain gush bolus clears, annihilation, scrub and polish. The pollution that the material that obliterates to be kept clear of before likely with mechanical method, polishing material or annihilation material cause. All all sorts of pollution especially grain of ab extra iron becomes cankerous source possibly, it is especially in damp environment. Accordingly, machinery clears the surface is best ought to undertake clearing normally below dry condition. Use machinery law can clear only its surface, of unalterable material itself fight corrode ability. Because this suggests to use polishing device after machinery clears new polish, use polishing dried meat to close.
Appearance is commonly used stainless steel brand and function
1, 304 stainless steel. It is application measures one of austenite stainless steel with bigger, the widest scope of application, apply to make rush greatly shape component and reality of conduit losing sick at heart, container, structural member, of all kinds appearance, also can make without equipment of magnetism, low temperature and component.
2, 304L stainless steel. Be in what the existence below a few conditions corrodes the tendency between serious brilliant and develop to exceed stainless steel of low carbon austenite to because Cr23C6 separate out causes 304 stainless steel,be solved, its sensitize condition is able to bear or endure ability is corroded between brilliant remarkable excel 304 stainless steel. Divide intensity a bit low outside, other function is the same as 321 stainless steel, solution treatment cannot have again after basically be being used at needing to solder be able to bear or endure corrode equipment and component, can use at making reality of of all kinds appearance wait.
3, 304H stainless steel. The in-house branch of 304 stainless steel, carbolic quality mark is in 0.04% , 0.10% , excel of high temperature capability 304 stainless steel.
4, 316 stainless steel. Person molybdenum is added on 10Cr18Ni12 steel foundation, make steel is had be able to bear or endure goodly reproducibility medium and be able to bear or endure spot corrosion ability. Mix in seawater other in all sorts of medium, corrosion resistance excel 304 stainless steel, basically use at be able to bear or endure to burn corrode material.
5, 316L stainless steel. Exceed mild steel, have be able to bear or endure goodly the function that corrodes between sensitize form any crystalline substance, apply to those who produce large sectional size to solder component and equipment, be able to bear or endure mediumly like petro-chemical equipment corrode material.
6, 316H stainless steel. The in-house branch of 316 stainless steel, carbolic quality mark is in 0.04% , 0.10% , excel of high temperature capability 316 stainless steel.
7, 317 stainless steel. Be able to bear or endure bit of corrode and fight stainless steel of 316L of creep ability excel, use at making petrifaction reach to be able to bear or endure the equipment that organic acid corrodes.
8, 321 stainless steel. Titanium stabilizes the austenite stainless steel that convert, add titanium to rise be able to bear or endure function is corroded between brilliant, have good high temperature mechanical function, usable exceed stainless steel of low carbon austenite to replace. Divide high temperature or fight hydrogen to corrode outside waiting for special situation, general situation is not recommended use.
9, 347 stainless steel. Niobium stabilizes the austenite stainless steel that convert, add niobium to rise be able to bear or endure function is corroded between brilliant, wait in acerbity, alkaline, salt corrode medium to be able to bear or endure mediumly corrode sex is the same as 321 stainless steel, weldability can be good, can make be able to bear or endure corrode material can make refractory steel use again, basically use at domain of igneous report, petrifaction, if make container, conduit, heat exchanger, rod kind, the heat pipe in industrial furnace and heat pipe thermometer.
10, 904L stainless steel. Stainless steel of super and complete austenite, it is Finnish Otto elder brother general (stainless steel of a kind of when OUTOKUMPU) company invents super austenite, mark of its nickel quality is 24% one 26% , carbolic quality mark is less than 0.02% , corrosion resistance is wonderful, have in be not oxidisability acid to be like vitriolic, acetic acid, formic acid, phosphoric acid be able to bear or endure very well corrode sex, have at the same time fight crevice corrosion goodly to reach fight stress to corrode function. Apply to all sorts of chroma are vitriolic under 70 ℃ , in often press next is able to bear or endure the in confusing sick at heart corrosion resistance of the acetic acid of any any chroma, temperature and formic acid and acetic acid is very good also. Original standard ASMESB-625 returns his the person nickel radical alloy, new standard puts in his 's charge for stainless steel. China has steel of 015Cr19Ni26Mo5Cu2 of similar shop sign only, the crucial material of manufacturer of instrument of a few Europe uses 904L stainless steel character, for example the mass flow of E+ H plan measure a canal to use 904L stainless steel namely, the watchcase of labor person watch also uses 904L stainless steel.
11, 440C stainless steel. Martensite stainless steel, be in but the hardness in stainless steel of rigid of temper by dipping in water, stainless steel is highest, hardness is HRC57. Basically use at making spray head, bearing, lever of the core of a powerful person of valve, valve base, sleeve, a powerful person.
12, 17-4PH stainless steel. Stainless steel of martensite precipitation sclerosis, hardness is HRC44, have high strenth, hardness and corrosion resistance, cannot use at prep above the temperature of 300 ℃ . Have to atmosphere and attenuant acid or salt fight goodly corrode ability, its fight corrode ability is mixed with 304 stainless steel 430 stainless steel are same, use at creating maritime platform, turbine lamina, lever of the core of a powerful person of valve, valve base, sleeve, a powerful person.
In appearance major, combine versatility and cost issue, choice of groovy austenite stainless steel is 304-304L-316-316L-317-321-347-904L stainless steel orderly, among them 317 use lesser, 321 do not recommend, 347 use at high temperature to fight corrode, the acquiescent material that 904L is component of individual firm share only is qualitative, in the design general won't advocate
Move choice 904L.
In the design type selecting of appearance, the circumstance that normally material of meeting occurrence appearance pledges with conduit material differs character, be in especially high temperature operating mode, be about special attention the design temperature that whether the alternative with appearance simple material satisfies technological equipment or conduit and design pressure, for example conduit is high temperature chromic molybdenum steel, and appearance chooses stainless steel, give an issue probably at this moment, must go consulting the thermobarometer with relevant qualitative material.
In appearance design type selecting, often come up against the stainless steel of all sorts of different systems, series, brand, the foundation wants when type selecting specific craft medium, temperature, pressure, component getting power, corrode, the much angle such as cost considers an issue.
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