What does it mean to add 08 or 03 after the stainless steel signal 30408

It is the difference in carbon content, S30408 (304), S30403 (304L) The number at the end of this stainless steel grade is the range of carbon content, 03 means that the carbon content belongs to ultra-low carbon stainless steel, similar to S31603 (316L), S31608 (316), in general, there is little difference between the performance of the two stainless steels, but S30403 with lower carbon content is easier to meet the requirements of the process, and it is slightly more expensive, because the carbon content is lower. The less likely it is to form chromium carbide during heat treatment, the corrosion resistance mainly depends on the chromium (CR) in the crystal, and the chromium carbide should flow to the grain boundary to reduce the CR in the crystal, resulting in poor corrosion resistance of stainless steel. Nowadays, almost all of them use S30403, and S30408 is rarely used. In fact, S30403 is a national standard 304L is a foreign standard, S30403 is equivalent to a domestic imitation of foreign 304L, 304L is not much to see, 316L domestic and foreign are different, in the early years, some demanding machinery factories strictly required the use of foreign 316L instead of domestic S31603, ** is not the same, now with the improvement of domestic technology, most of them are also using domestic ones.

S30408] corresponds to the domestic grade: 06CR19Ni10, which belongs to austenitic stainless steel, which is a general-purpose stainless steel, which is widely used in the production of equipment and parts that require good comprehensive performance (corrosion resistance and formability). To maintain the corrosion resistance inherent in stainless steel, the steel must contain more than 12% chromium.

06CR19Ni10 is the most widely used stainless steel and heat-resistant steel. It is used in food production equipment, general chemical equipment, nuclear energy, etc. The specific grades correspond as follows:

Chemical Composition: Carbon%: Silicon%: Manganese%: Phosphorus%: Sulfur%: Nickel%:; Chromium %:.

S30408 is 06Cr19Ni10 steel plate S30403 is 022Cr19Ni10 steel plate See GB24511-2009 standard for detailed comparison table.

30408 is a pressure vessel plate, and the implementation standard 24511-2009 08 is such as 22 thick plates must be reached.

It's a new grade, with a unified numerical code: S30408=SUS304 S30403=SUS304L, but I don't know what 08 and 03 mean.

I don't know if what you said is abbreviated in front of UNS If there is UNS, it is the American standard, if not, it is the national standard, you can refer to GB T1220-2008 "Stainless Steel Bar" or GB T20878-2007 "Stainless Steel and Heat-resistant Steel Grades and Chemical Composition", but look at the numbers and estimate that it is the national standard, S30408 is the previous 0Cr18Ni9 (304), S32168 is the former 0Cr18Ni10Ti (321), S31603 is 00cr17ni14mo2 (316L).

S30408 is equivalent to 304 stainless steel (0Cr18Ni9).

S32168 is equivalent to 321 stainless steel (1Cr18Ni9Ti).

S31603 is equivalent to 316 stainless steel (022Cr17Ni12Mo2).

S31603 is what everyone often calls 316L. This can be said to be a low-carbon version of 316, and the carbon content does not exceed that. Its main advantage is that it can not be heat treated after welding.

S1 is the code name for ferritic stainless steel.

S2 is the code name for austenitic-ferritic stainless steel.

S3 is the code name for austenitic stainless steel.

S30408 belongs to austenitic stainless steel, corresponding to China's new grade: 06Cr19Ni10, old grade: 0Cr18Ni9

Executive standard: GB T 20878-2007 stainless steel and heat-resistant steel grades and chemical composition.

GB T 24511-2017 Stainless steel plate and steel strip for pressure equipment.

GB T 4237-2015 Stainless Steel Hot Rolled Steel Plate and Steel Strip.

NB T 47010-2017 Stainless steel and heat-resistant steel forgings for pressure equipment.

S30408 Chemical Composition:

S --- the first letter of stainless steel in English.

304--American stainless steel code, similar to 0CR19NI10 in China's national standard GB1220.

It is certain that 08 does not represent carbon content, for example: S32168 is a grade of 321 that implements the GB T24511-2009 standard, but the carbon content is not.

The uniform numerical code format is fixed at 6 digits, with letters as the prefix followed by 5-digit Arabic numerals. The first letter represents different types of steel products, generally the first letter of English words, such as "S" for stainless steel, "A" for alloy steel; The second digit is the classification code, such as "S3" for austenitic stainless steel, and the next four digits represent the sequential coding of the steel number. The unified numerical code is S30408, which means austenitic stainless steel, and the sequential number is 0408.

I can't say which one is better, ** there are differences in cost performance.

S30408 is a commonly used stainless steel material, which is equivalent to 06Cr19Ni10 under China's GB standard.

The specific meaning of the numbers in the UNS number of common materials:

1. S S represents AISI and SAE stainless steel and heat-resistant steel;

2. The first three indicate the type of stainless steel;

3. The first one represents: 1 is precipitation hardening stainless steel, 2 is Cr-mn-Ni-N austenite, 3 is Cr-Ni austenite, 4 is high Cr martensitic and low-carbon high-Cr ferrite, 5 is low-carbon martensite;

4, the second and third indicate the classification number of the type of steel;

5. The fourth and fifth represent the material sequence number (distinguish the difference between individual components, 00 is no difference).

Advantages and applicability:

06Cr19Ni10 stainless steel is one of the most widely used chromium-nickel stainless steels, with good corrosion resistance, heat resistance, low temperature strength and mechanical properties.

06CR19Ni10 is suitable for food processing, storage and transportation. It has good processability and weldability. Plate heat exchangers, bellows, household goods, building materials, chemicals, food industry, etc.

30403 is ordinary, 304 corresponds to the national standard is GB4237, 30408 is the pressure vessel standard, the corresponding national standard is GB24511, the composition of the two is different, the latter P, S content is below, the former P S content is below, there is no difference in the others, and there is a difference in the tolerance difference, the latter tolerance is smaller.

30408 is mainly used in high-voltage environments, and this is the same as 30403.

None of them are good, and the bad ones are on the middle 4.

304 stainless steel is the most common general stainless steel material on the market, although the name of 304 is very common in China, but the name "304" is authentic American, generally means ASTM standards. Another common 304 representation method, SUS304, comes from Japan and is produced according to the Japanese standard. The latest grade of 304 in China is 06cr19ni10, and the industry also calls 304 stainless steel 18 8 stainless steel, which means that the normal circulation of 304 has a chromium content of 18 chromium and a nickel content of 8 nickel.

S30408 stainless steel, is a domestic name for stainless steel for pressure equipment, its digital code is S30408, it is the same as 304, also 06CR19NI10. The difference is that S30408 is produced in accordance with the GB-T 24511-2017 standard "Stainless Steel and Heat-Resistant Steel Plate and Steel Strip for Pressure Equipment", which is mainly used for pressure equipment such as pressure vessels. If the steel mill wants to produce S30408, it must obtain the corresponding production certification, and the 304 produced can be called S30408, otherwise it can only be called 304.

The last two digits represent the carbon content, the carbon content of S30408 is, and the carbon content of S30409 is. For details, please refer to GB T20878-2007. If the carbon content is high, mild is better, but at the same time, the corrosion resistance will be reduced.

Among them, the carbon content of S30409 is a relatively large range, and my personal understanding is to make a relatively loose material standard, used in some places that are not demanding, and the carbon content range is large, which helps to reduce the processing technology, thereby reducing costs.

S30408 belongs to austenitic stainless steel, corresponding to China's new grade: 06Cr19Ni10, old grade: 0Cr18Ni9

Executive standard: GB T 20878-2007 Stainless steel and heat-resistant steel grades and chemical compositions GB T 24511-2017 Stainless steel steel plate and steel strip for pressure-bearing equipment GB T 4237-2015 Stainless steel hot-rolled steel plate and steel strip NB T 47010-2017 Stainless steel and heat-resistant steel forgings for pressure-bearing equipment S30408 Chemical composition:

Look at the grade arrangement series, such as the stainless steel numbered by the United States UNS, but the American grade does not have the grade you said, only S30400 and S30409 grades. It is estimated that your expectations are too high, and the Americans have not yet had time to develop them.

2. Corrosion resistance in the atmosphere, in industrial atmosphere and heavily polluted areas, in order to avoid corrosion, it needs to be cleaned in time. Suitable for food processing, storage and transportation. Plate heat exchangers, bellows, household goods, building materials, chemicals, food industry, etc., have good processing performance and weldability.

3. When the S30408 material is heated, the surface is attached with oil, and the thickness of the scale at the oil attachment part is different from the thickness of the scale in other parts, resulting in carburizing, and the carburized part of the base metal under the oxide skin is seriously eroded by acid. In this way, the material of S30408 is best degreased with trichloroethylene degreaser and caustic soda solution, and then washed with warm water, and then heat treated.

GB T 20878 No.: 17

Uniform numerical code: S30408

New grade: 06CR19Ni10

Old grade: 0Cr18Ni9

Mass Fraction %|c:

Mass Fraction %|si: 1

Mass Fraction %|mn: 2

Mass Fraction %|p:

Mass Fraction %|s:

Mass Fraction %|ni: 8～11

Mass Fraction %|cr: 18～20

Mass Fraction %|mo: —

Mass Fraction %|cu: —

Mass Fraction %|n: —

Mass Fraction %|Other elements: —

S30403 and S30408 are both Cr18, Ni9 type austenitic stainless steel, the difference between the two is the carbon content of S30403 and the carbon content of S30408.

S30403 and S30408 both belong to the GB24511 pressure BAI vessel standard materials DU Colloquially answer you, similar to 304L and 304, that is, carbon content.

The differential varieties of the DAO are distributed as and, and the other components of S30408 contain n other components consistent with the benefits of low carbon, and the ability to resist intergranular corrosion is strong.

The 2 stainless steel materials in No. 304 do not contain carbon so they do not corrode, and they are considered to be 2 kinds of high-grade stainless steel, and the 304408 is better than 304403

The 2 stainless steel materials in No. 304 do not contain carbon so they do not corrode, and they are considered to be 2 kinds of high-grade stainless steel, and the 304408 is better than 304403

S30403 and S30408 are DU materials of the BAIGB24511 pressure vessel standard

A: Other ingredients are the same.

Low carbon benefits, strong resistance to intergranular corrosion.

S30408 is austenitic stainless steel, which is different from S304 stainless steel.

1. The raw materials are different.

S30408 and 304 are not the same raw material, S30408 is a domestic austenitic stainless steel grade, S304 is a foreign standard, in addition, its CR content is also different, in short, S30408 indicators are better than S304.

2. The essence is different.

S30408 is the UNS number, is the stainless steel material, the carbon content of S30408 is, the carbon content of S30409 is. If the carbon content is high, mild is better, but the corrosion resistance will be reduced.

304 stainless steel is a common raw material in stainless steel, with a density of 18 8 stainless steel in the industry. High temperature resistance of 800 degrees, with good processing function, high toughness characteristics, widely used in industry and furniture decoration occupations and food and medical occupations.

3. Different uses.

304 is a versatile stainless steel that is widely used in the manufacture of equipment and components that require outstanding versatility (corrosion resistance and formability). In order to maintain the corrosion resistance inherent in stainless steel, it is necessary for the steel to contain more than 18% chromium and more than 8% nickel. 304 stainless steel is a trademark of stainless steel produced in accordance with the American ASTM specification.

SUS304 (austenitic stainless steel), on the other hand, is a general-purpose stainless steel that is widely used in the manufacture of equipment and parts that require good overall properties (corrosion resistance and formability).