Stainless steel in metallurgy also called as inox steel or just inox. The Properties of general steel have been modified become better properties like stand to corrode, this kind of steel is called as steel alloy or alloy steel. The properties of stainless steel better because this alloy steel content of chromium content about 10.5% by weight. Which is chromium is a substance that stand to corrode. Stainless steel have variety product that each product have different characteristic and have different level of corrosion stand. The usual stainless steel will stand to rust cause by bad environment like water, salt water, little low acid or base chemicals. The composition of this alloy steel depend on the type of stainless steel, and each type have different characteristic.
Type of Stainless Steel
Stainless steel type 304 is lower grade or usual stainless steel. This stainless still less stand to acid other chemicals substance like cellulose acetate, air content acid vapor etc. This steel may better for build water tank or low base chemical tank or storage.
The higher type of stainless steel are type 316 and 317, both stainless steel useful for chemical storage like acetic acid, sodium hydroxide, and other chemicals with little acid. But for sulfuric acid is not stand for long time. Stainless steel 317 have better resistance than 316 stainless steel and longer stand to bad environment than 316 type, but stainless steel 317 also can’t stand too long to sulfuric acid or high acid condition.
Highest level of stainless steel is stainless 316L this stainless steel usually use in chemical industry like sulfuric acid, sodium hydroxide, sodium hypo-chloride or urea industry. Stainless steel 316L use on their piping system, processing equipment, and storage tanks. All type of stainless steel normally good to in aldehydes and amines such as urea formaldehyde and melamine formaldehyde.
Electric and Magnetism Properties of Stainless Steel
Stainless steel have poor conductivity cause this steel have mixed with other substance (chromium) in their composition and make this mixing have bad electricity conductor. Stainless steel have non-magnetic properties, usually for higher than stainless steel 304 type. This properties can slightly change if stainless steel is hardened or heat up in high temperature. Stainless steel properties can change like stand to corrosion also can change.
Austenitic Stainless Steel
On choosing material for construction whether the steel must stand to certain condition that fulfill to the process operation. If the material will use in high temperature and resistance to oxidize process and resistance to carburetion you may choose Austenitic Stainless Steel product.The characteristic of Austenitic Stainless Steel Product as follows:
- Good creep strength
- Good structural stability at high temperatures
- Very good resistance to isotherm and cyclic oxidation
- Very good resistance to carburization
- Good corrosion resistance
- Good weld-ability
Under corrosive conditions in general ( e.g. at ambient temperature) this grade is comparable or somewhat superior to Sandvik 1000SA (AISI316). These properties make this grade the ideal choice for elevated temperature service especially at temperatures equal to or above 600 ºC (1112 ºF).
Creep strength
The creep and creep rupture strength values correspond to values evaluated by the Swedish Institute for Metals Research for inclusion in the Swedish Standard. The evaluation is based on data Materials Technology and Outokumpu Stainless and tests made by the Swedish Institute for Metals Research. The basic values have been determined by testing at intervals of 100°C and at 750°C (1380°F), under uni-axial stress and with a constant load. The mean values in the tables below have been evaluated from the test results with the aid of linear regression of the logarithmic relationship between stress and time. This evaluation also provides the basis of interpolation and extrapolation of temperature and time. The temperature above which design calculations are based on creep rupture strength, instead of Rp0.2 proof strength, can be read off, this temperature is about 550°C (1020°F).Mechanical Properties of Stainless Steel
The properties of stainless steel is perform at room temperature, on the text book usually compare to elevated temperature, what the effect to stainless steel if any temperature changes. This characteristic can draw how danger of any structure in special condition like on fire or any earth quake.
Many parameter in mechanical properties, but you just need to watch and compare of yield strength properties and tensile strength properties. Stainless steel is coded by the type and grade as the composition of stainless alloy. Stainless steel grade by the code of EN 1993-1-2 for steel grades 1.4003, 1.4301, 1.4401, 1.4571, 1.4003 and 1.4462.
The graph of properties each stainless steel grade as follows, yield strength is drawn with fy, and tensile strength with fu.
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| Stainless Steel Properties |
Stainless Steel Products:
Stainless steel have good properties that stand to corrosion and this steel also can be proceed become bright surface, so stainless steel have been applied in many products such as in house hold, spare parts, industrial parts and structure. These are several example of stainless steel products: |
| house ware |
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| house hold |
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| spare part |
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| Industrial parts |
