One of the most versatile and commonly used stainless steels on the market, Grade 304 stainless steel is the most standard used alloy of this type. Essentially, Grade 304 is an austenitic chromium alloy which is also known as an “18/8” stainless as the make-up of the steel is 18% chromium and 8% nickel.

The chromium content promotes the material’s considerable resistance to the effects of corrosion and oxidation. The stainless steel alloy resists most oxidizing acids and will withstand ordinary rusting though this does not mean that the steel will not tarnish over time. The steel needs to be cold worked to generate higher tensile strength. For stainless steel sections which are welded heavily, post-weld annealing may be necessary to provide maximum corrosive resistance.

Type 304 Stainless Steel has excellent welding and deep drawing characteristics – it is easy to fabricate, easy to clean and aesthetically pleasing to the eye.

304 Stainless Plate, the most widely used of the stainless and heat resisting steels. 304 stainless plate offers good corrosion resistance to many chemical corrodents as well as industrial atmospheres and marine environments Typical specifications for 304 Plate and 304L. Stainless Steel Plate are ASTM A-240, ASME SA -240 and A666.

304 Stainless Steel Plate has very good formability and can be readily welded by all common methods. 304/304L dual certified.

The most common type of stainless steel in use is grade 304. This grade has an 18-20% chromium content and a 8-10.5% nickel content by mass, although 304L exists as a low-carbon alternative to 304, and 304Cu and 304N versions, enriched in copper and nitrogen respectively, also exist. This type of steel is also often referred to as A2 stainless steel. Grade 304 offers an impressive strength, as well as incredible corrosion resistance, lending it to applications in which contact with food, chemicals or fresh water must be tolerated. Type 304 stainless steel also has properties which make it well suited to welding and machining applications, thereby making it an excellent material for use in making machined parts.

304L stainless

304L stainless is a lower carbon variant of Grade 304 – the steel can be welded without the resulting issue of carbon precipitation (precipitation of chromium carbide as heat is applied during the welding process which depletes the chromium element of the steel thus reducing its anti-corrosive/oxidation effectiveness).

As a result, Type 304L stainless steel is a sort after material for use in severely corrosive conditions. Weld annealing is only necessary in applications where stress loads are excessive.

This steel Grade is found in a variety of commercial sectors, particularly in the chemical industry.

Benefits of using 304L Stainless Steel

Low carbon content eliminates carbon precipitation in the welding process
Can be used in severe corrosive environments
Weld annealing only required in high stress applications
Very similar to Type 304

304 & 304L plate and pipes have similar properties and in certain cases are stocked with Dual Certification, where it is concluded that each item has properties and a composition which comply with both steel types. Grade 304H cannot be included in this equation due to the steel’s higher carbon content which is intended for use in elevated temperature applications.

304H stainless

304H stainless has a higher carbon content making the steel more suitable for use in applications where elevated temperatures are present. It is an austenitic chromium-nickel steel alloy and the greater carbon content delivers an increased tensile and yield strength.

The material is recommended for use in ASME pressure vessels in working service above 525 °C due to the grade’s heat resistant properties.

Benefits of using 304H Stainless Steel

Higher carbon content gives the material greater heat resistant qualities
Higher tensile yield strength
Greater short and long term creep strength

304H alloy is commonly found in the oil refining, gas and chemical industry and is used in industrial boilers, pressure vessels, heat exchangers, pipelines and condensers. The material is also used throughout the power generation industry.

Applications of Grade 304 Stainless Steel

The steel is common throughout industry particularly in food processing as the material is not susceptible to corrosion from acids found in common foodstuffs. As a consequence, such steel is ideal for items such as sinks, work surfaces, preparation areas and refrigerators. It is also a perfect material for use in the pharmaceutical industry for environments such as clean rooms.

Grade 304 can also be found in heat exchangers, chemical containers, pipelines and throughout the brewing industry. It can be used as a fabricated material where high temperature petroleum gases or steam production gases are stored such as pressure vessels. It can even be found extensively in the construction industry where the material is used for cosmetic purposes such as a building fascias.

Advantages/Disadvantages

This stainless steel grade is among the most common stainless steel grades, in part because it is so versatile and easy to fabricate. It shows good ductility in the annealed condition, and can be readily drawn and formed for complex shapes. High hardness and strength can be achieved through cold working. This grade demonstrates excellent corrosion resistance and will withstand rural and industrial atmospheric exposure, and weldments are less susceptible to intergranular fractures. One disadvantage is that 304 is non-hardenable by heat treatment.

Chemical composition of 304 stainless

Grade	C	Mn	P	S	Si	Cr	Ni	N
304	0.08% max	0.02	0.00045	0.03% max	0.75% max	18 - 20%	8 - 12%	0.1% max
304L	0.03% max	0.02	0.00045	0.03% max	0.75% max	18 - 20%	8 - 12%	0.1% max
304H	0.04-0.10	0.02	0.00045	0.03% max	0.75% max	18 - 20%	8 - 12%	0.1% max

Typical specifications for 304 Plate and 304L Stainless Steel Plate are ASTM A-240, ASME SA -240 and A666.
304 stainless steel,also known as 18/8 stainless steel, European norm 1.4301, is the most common stainless steel. The steel contains both chromium (usually 18%) and nickel (usually 8%) metals as the main non-iron constituents. It is an austenite steel. It is not very electrically or thermally conductive, and is non-magnetic. It has a higher corrosion resistance than regular steel and is widely used because of the ease in which it is formed into various shapes.

Grade 304L is the low carbon version of 304. It does not require post-weld annealing and so is extensively used in heavy gauge components.

Mechanical Properties of 304 Stainless

Data	Metric	Imperial
Tensile Strength, Ultimate	655 MPa	95 ksi
Tensile Strength, Yield	290 MPa	42 ksi
Elongation at Break (in 2")	0.55	0.55
Rockwell Hardness	B84	B84

304 Stainless Steel Plate has very good formability and can be readily welded by all common methods.

Specification of 304 stainless steel plate

Thickness of cold rolled steel plate	Thickness of galvanized steel sheet	Wearing plate+Corrosion resistance plate	Galvanized coil+Galvanized coil	Ction volume	Stainless steel plate	Thick plate
0.1mm	0.1mm	1.5mm	0.1mm	0.1mm	1.5mm	18mm
0.2mm	0.2mm	2.0mm	0.2mm	0.2mm	2.0mm	20mm
0.3mm	0.3mm	2.5mm	0.3mm	0.3mm	2.5mm	22mm
0.4mm	0.4mm	2.75mm	0.4mm	0.4mm	2.75mm	25mm
0.5mm	0.5mm	3.0mm	0.5mm	0.5mm	3.0mm	28mm
0.6mm	0.6mm	3.5mm	0.6mm	0.6mm	3.5mm	30mm
0.7mm	0.7mm	3.75mm	0.7mm	0.7mm	3.75mm	32mm
0.8mm	0.8mm	4.0mm	0.8mm	0.8mm	4.0mm	35mm
0.9mm	0.9mm	4.5mm	0.9mm	0.9mm	4.5mm	40mm
1.0mm	1.0mm	4.75mm	1.0mm	1.0mm	4.75mm	42mm
1.2mm	1.2mm	5.0mm	1.2mm	1.2mm	5.0mm	45mm
1.3mm	1.3mm	5.5mm	1.3mm	1.3mm	5.5mm	48mm
1.4mm	1.4mm	5.75mm	1.4mm	1.4mm	5.75mm	50mm
1.5mm	1.5mm	6.0mm	1.5mm	1.5mm	6.0mm	52mm
1.6mm	1.6mm	6.5mm	1.6mm	1.6mm	6.5mm	55mm
1.8mm	1.8mm	6.75mm	1.8mm	1.8mm	6.75mm	58mm
1.9mm	1.9mm	7.5mm	1.9mm	1.9mm	7.5mm	60mm
2.0mm	2.0mm	7.75mm	2.0mm	2.0mm	7.75mm	62mm
2.1mm	2.1mm	8.0mm	2.1mm	2.1mm	8.0mm	65mm
2.2mm	2.2mm	8.5mm	2.2mm	2.2mm	8.5mm	68mm
2.4mm	2.4mm	8.75mm	2.4mm	2.4mm	8.75mm	70mm
2.5mm	2.5mm	9.5mm	2.5mm	2.5mm	9.5mm	72mm
2.6mm	2.6mm	9.75mm	2.6mm	2.6mm	9.75mm	75mm
2.7mm	2.7mm	10mm	2.7mm	2.7mm	10mm	80mm
2.8mm	2.8mm	10.5mm	2.8mm	2.8mm	10.5mm	82mm
3.0mm	3.0mm	11.5mm	3.0mm	3.0mm	11.5mm	85mm
3.2mm	3.2mm	11.75mm	3.2mm	3.2mm	11.75mm	90mm
3.4mm	3.4mm	12mm	3.4mm	3.4mm	12mm	100mm
3.5mm	3.5mm	12.5mm	3.5mm	3.5mm	12.5mm	110mm
3.6mm	3.6mm	12.75mm	3.6mm	3.6mm	12.75mm	120mm
3.8mm	3.8mm	13.75mm	3.8mm	3.8mm	13.75mm	140mm
4.0mm	4.0mm	14mm	4.0mm	4.0mm	14mm	150mm
4.2mm	4.2mm	14.5mm	4.2mm	4.2mm	14.5mm	160mm
4.5mm	4.5mm	14.75mm	4.5mm	4.5mm	14.75mm	170mm
4.6mm	4.6mm	15mm	4.6mm	4.6mm	15mm	180mm
4.8mm	4.8mm	15.5mm	4.8mm	4.8mm	15.5mm	190mm
5.0mm	5.0mm	16mm	5.0mm	5.0mm	16mm	200mm

PMI Test Plate

Positive material identification (PMI) is used to analyse and identify material grade and alloy composition for quality and safety control. A rapid, non-destructive method, positive material identification is performed on a wide range of components and assets, and provides a semi-quantitative chemical analysis.

Processing Technology Of 304 Steel plate

With the development of science and technology and industry, the materials put forward higher requirements, such as higher strength, resistance to high temperature, high pressure, low temperature, corrosion resistance, wear and other special physical and chemical properties of the requirements, carbon steel has been unable to fully meet the requirements.

Deficiency of carbon steel:
(1) Low hardenability. In general, the maximum quenching diameter of carbon steel water quenching is only 10mm-20mm.

(2) Relatively low strength and buckling. For example, the σ S of ordinary carbon steel Q235 steel is 235MPa, while the σ S of low alloy structural steel 16Mn is more than 360MPa. The σ S /σ B of 40 steel is only 0.43, which is much lower than that of alloy steel.

(3) Poor tempering stability. Because of the poor tempering stability, carbon steel in the quenching and tempering treatment, in order to ensure higher strength to use a lower tempering temperature, so that the toughness of steel is low; In order to ensure better toughness, the strength of high tempering temperature is low, so the comprehensive mechanical properties of carbon steel is not high.

(4) Can not meet the requirements of special performance. Carbon steel in oxidation resistance, corrosion resistance, heat resistance, low temperature resistance, wear resistance and special electromagnetic and other aspects are often poor, can not meet the needs of special performance.

Frequently Asked Questions

What is the difference between 304 and 304L?

304L is the ultra low carbon variant of 304 stainless. Lower carbon content is the only chemical difference between these two grades, leading 304L to perform better in corrosive environments and be easier to weld.

Why is 304L better for welding than 304?

The lower carbon content in 304L eliminates chromium carbide precipitation caused during welding, putting 304L at lower risk for intergranular corrosion even in highly corrosive environments.

316 vs 304 Stainless Steel: Which is Better?

When comparing 304 stainless steel vs 316, they both have pros and cons to consider when deciding which one to use for different applications. For instance, 316 stainless steel is more resistant than 304 to salt and other corrosives. So, if you are manufacturing a product that will often face exposure to chemicals or a marine environment, 316 is the better choice.

On the other hand, if you are manufacturing a product that does not need strong corrosion resistance, 304 is a practical and economical choice. For many applications, 304 and 316 are actually interchangeable.

Corrosion Resistance

Alloy 304/304H has good resistance to atmospheric corrosion, foods and beverages and to many organic and inorganic chemicals in moderately oxidizing to moderately reducing environments. The high chromium content of the alloy provides resistance to oxidizing solutions such as nitric acid up to 55% weight and up to 176°F (80°C).

Alloy 304/304H also resists moderately aggressive organic acids such as acetic. The nickel present in the alloy provides resistance to moderately reducing solutions such as pure phosphoric acid, whatever the concentration, in cold solutions and up to 10% diluted hot solutions. The alloy can also operate successfully in caustic solutions free of chlorides or fluorides at moderate temperatures.

Alloy 304/304H does not perform well in more highly reducing environments such as those containing chlorides and sulfuric acid.

Alloy 304/304H performs well in fresh water service with low levels of chlorides (less than 100ppm). At higher chloride levels the grade is susceptible to crevice corrosion and pitting. For successful performance under these more severe conditions, higher molybdenum content is need such as 316/316L. Alloy 304/304H is not recommended for service in marine environments.

In most instances, the corrosion resistance of Alloys 304, 304L and 30H will be roughly equal in most corrosive environments. However, in environments that are sufficiently corrosive to cause intergranular corrosion of welds and heat-affected zones Alloy 304L should be used because of its low carbon content.

How to distinguish the quality of 304 stainless steel plate

With the improvement of people’s standard of living, 304 stainless steel is increasingly used, and there are more and more304 stainless steel manufacturers. Of course, it will inevitably be mixed with poor quality, which is very important for customers. It is said that how to choose has become a big headache. 304 stainless steel has a smooth surface, high plasticity, toughness and mechanical strength, and is resistant to corrosion by acids, alkaline gases, solutions and other media. It is an alloy steel that does not rust easily but is not free of rust. 304 stainless steel plate refers to a steel plate that is resistant to corrosion by weak means such as atmosphere, steam and water, while acid-resistant steel plate refers to steel plate that is resistant to corrosive chemical means such as acids, alkalis, and salt The following 304 stainless steel plate manufacturers will teach you how to distinguish the quality of stainless steel plates.

There should be no scratches on the surface of the stainless steel plate. This is a more critical point that directly affects thequality of the stainless steel mirror panel. If there are scratches on the 2B plate of the stainless steel raw material, the minor ones can be removed in the process of polishing the mirror surface (8K), and the deeper scratches cannot be removed. If scratches are left after polishing the mirror surface, there is no way to remove them. Generally speaking, newly left scratches are caused by workers not paying attention to the operation process during operation, and scratched lines are new, the scratch surface is relatively sharp, while the scratch on the plate is relatively smooth after grinding the mirror surface
There should be no trachoma on the 304 stainless steel surface. Trachoma is a small hole that can be seen with the naked eye on the panel. This is also a very important point. The appearance of trachoma has a lot to do with the raw material.
The 304 stainless steel plate cannot have the grinding head pattern. The grinding head pattern is circle after circle, which is the mark left by the grinding head of the 8K machine and equipment, without good contact.

4.304 stainless steel platecannot have roller footprints. This is left by the rollers of the 8K machine, which are rows of roller footprints.