SA240 gr 321 Properties and Aplications

SA240 gr 321 is a type of stainless steel produced in accordance with ASTM A240 standard, which is often used in high-temperature and corrosive environments.

SS 321 Plate Equivalent grades

JIS G4304	ASTM	UNS	KS	EN10095	AS	CNS
SUS321	321	S32100	STS321	1.4541	321	321

Chemical composition:

Type	Grade
	ASTM (A240M)	Others (JIS)	C	Si	Mn	P	S	Ni	Cr
Austenitic Steels
	321	SUS321	≤0.08	≤0.75	≤2.00	≤0.045	≤0.030	9.0/12.0	17.0/19.0

Titanium (Ti): a minimum of 5 times the carbon (C) content, but not more than 0.70%.

Physical Properties

Grade	Density (kg/m3)	Elastic Modulus (GPa)	Mean Coefficient of Thermal Expansion (μm/m/°C)			Thermal Conductivity (W/m.K)		Specific Heat 0-100 °C (J/kg.K)	Electrical Resistivity (nΩ.m)
			0-100 °C	0-315 °C	0-538 °C	at 100 °C	at 500 °C
321	8027	193	16.6	17.2	18.6	16.1	22.2	500	720

Mechanical Properties

Type	Mechanical Properties for Stainless Steel Plates, Stainless Steel Sheet
	ASTM (A240M)	Others (JIS)	Tensile Properties			Hardness
			Yield Strength (Mpa)	Tensile Strength (Mpa)	Elongation (%)	HBW			HRBW
Austenitic Steels
	321	SUS321	≥205	≥515	≥40	≤217			≤95

SA240 gr 321 has good corrosion resistance in environments containing nitric acid and organic salts. It also has good high-temperature strength and can be used at temperatures up to approximately 900 degrees Celsius.

Applications of SA240 gr 321 include:

• Components in the chemical and petrochemical industry
• Equipment in thermal power plants and nuclear power plants
• Heat-resistant equipment in the food and pharmaceutical industry
• Applications in the medical field, such as in dental equipment.

 

ASTM A990: Standard Specification for Duplex Stainless Steel Castings

ASTM A990 is a standard specification for duplex stainless steel castings used in pressure-containing applications such as valves, flanges, and fittings. This standard covers five different grades of duplex stainless steel castings, each with unique properties and characteristics.

The five grades covered by ASTM A990 include CD3MN, CD4MCu, CD4MCuN, CE3MN, and CE8MN. CD3MN is a duplex stainless steel with a high chromium content and moderate amounts of nickel, molybdenum, and nitrogen. It offers good corrosion resistance in various environments, including seawater, and is often used in valves, pumps, and other pressure-containing components.

CD4MCu is a duplex stainless steel with higher levels of chromium, molybdenum, and copper than CD3MN. It has excellent resistance to pitting and crevice corrosion and is commonly used in marine and chemical processing applications.

CD4MCuN is a modified version of CD4MCu that also contains nitrogen for improved corrosion resistance. This grade is well-suited for applications in harsh environments, such as offshore oil and gas production.

CE3MN is a duplex stainless steel with a high nitrogen content and low nickel content. It offers good resistance to corrosion and stress corrosion cracking in chloride-containing environments and is often used in chemical processing and pulp and paper production.

CE8MN is a duplex stainless steel with higher levels of nitrogen and molybdenum than CE3MN. It has excellent resistance to pitting and crevice corrosion and is often used in seawater applications.

The mechanical properties of the duplex stainless steel castings specified in ASTM A990 depend on the grade and the heat treatment process. The minimum tensile strength and yield strength requirements for each grade are specified in the standard, as well as the maximum hardness values.

ASTM A990 also specifies the chemical composition and testing requirements for each grade of duplex stainless steel castings. The chemical composition requirements ensure that the castings meet the specified corrosion resistance and mechanical properties, while the testing requirements ensure that the castings meet the quality standards set forth in the specification.

In conclusion, ASTM A990 is an important standard specification for duplex stainless steel castings used in pressure-containing applications. Understanding the different grades and their properties can help engineers and designers select the appropriate material for their specific application. By following the requirements set forth in ASTM A990, manufacturers can ensure that their duplex stainless steel castings meet the necessary quality and performance standards

 

Composition, Properties, and Applications of A240 type TP410

ASTM A240/A240M is a standard specification for chromium and chromium-nickel stainless steel plate, sheet, and strip for pressure vessels and for general applications.

The most commonly used grades are the austenitic grades such as 304, 304L, 316, and 316L, which have a high content of chromium and nickel and offer good corrosion resistance, high strength, and good formability. Other grades include ferritic and martensitic grades such as 409, 410, 430, and 440C, which offer good resistance to high-temperature and corrosive environments.

A240-TP410 is a martensitic stainless steel alloy that is commonly used in applications where high strength, hardness, and corrosion resistance are required. This alloy is also known as UNS S41000, which is its standard designation according to the Unified Numbering System (UNS).

Equivalent grades

TP410 is a martensitic stainless steel that is equivalent to several other grades of stainless steel, including:

• AISI 410
• UNS S41000
• EN 1.4006
• JIS SUS410
• GB/T 10Cr13

Composition: 

The primary alloying element in TP410 is chromium, which is present in concentrations of 11.5% to 13.5%. Carbon is also a significant component, with concentrations ranging from 0.08% to 0.15%. Other alloying elements present in smaller amounts include manganese, silicon, phosphorus, sulfur, and nickel. This composition gives TP410 its characteristic high strength, hardness, and corrosion resistance.

Properties: 

TP410 is known for its high mechanical properties, including excellent tensile and yield strength. It has a high hardness, which makes it resistant to wear and abrasion. TP410 also exhibits good corrosion resistance in mildly corrosive environments, although it is not as corrosion-resistant as some other stainless steel alloys, such as austenitic grades.

Mechanical properties

The mechanical properties of TP410 depend on various factors such as the heat treatment, manufacturing process, and other conditions.

Typically, TP410 has a tensile strength of 480 MPa (70 ksi) and a yield strength of 275 MPa (40 ksi). The elongation at break is usually around 20% and the hardness ranges from 170 to 255 HBW (Brinell Hardness).

In terms of impact toughness, TP410 exhibits moderate to high impact strength. The Charpy V-notch impact toughness is usually around 35 Joules (25 ft-lb) at room temperature. However, the impact toughness can vary depending on the temperature and the heat treatment conditions.

It is important to note that the mechanical properties of TP410 can be improved through appropriate heat treatment, such as quenching and tempering. This can result in higher strength and hardness, as well as improved toughness.

Applications: 

TP410 is commonly used in applications such as pumps, valves, and other equipment that operate in corrosive environments, such as those found in the chemical and petrochemical industries. It is also used in the construction of heat exchangers, reactors, and other process equipment.

In addition, TP410 is often used in the manufacturing of surgical and dental instruments, as well as in the production of blades and other cutting tools. Its high strength and hardness make it an ideal material for these types of applications.

Conclusion: 

TP410 is a widely used martensitic stainless steel alloy that offers high strength, hardness, and corrosion resistance. Its composition and properties make it ideal for a range of applications, particularly those in corrosive environments. While it may not be as corrosion-resistant as some other stainless steel alloys, its high strength and hardness make it a popular choice for many industrial and manufacturing applications.

 

Difference Between 304 304L and 321

304 stainless steel is low carbon chromium nickel stainless and heat resisting steel somewhat superior to Type 302 in corrosion resistance.

321 stainless steel is known as stabilized grades of stainless steel, is Chromium nickel steel containing titanium. Recommended for parts fabricated by welding which cannot be subsequently annealed. Also recommended for parts to be used at temperatures between 800°F and 1850°F (427 to 816°C), have good properties resistance to intergranular corrosion. The titanium element in 321 stainless steel makes it more resistant to chromium carbide formation.

321 stainless steel is basically from 304 stainless steel. They different by a very very small addition of Titanium. The real difference is their carbon content. The higher the carbon content the greater the yield strength. 321 stainless steel has advantages in high temperature environment due to its excellent mechanical properties. Compared with 304 alloy, 321 stainless steel has better ductility and resistance to stress fracture. In addition, 304L can also be used for anti-sensitization and intergranular corrosion.

The real problem with most headers/upipes is a difference in the coefficient of thermal expansion (CTE) As you block gets hot it expands, as it cools it contracts. What you want is a material that expands and contracts at the same rate as your cast iron block. This allows the seals (gaskets/flanges) to undergo less stress. Most leaks (besides improper installation) are caused by this unmatched CTE. That is why stock exhaust manifold is cast iron, which really meany it has a 2% or more carbon content.

321=(17-19Cr, 9-12Ni + Titanium)

As for the dual designation theory, that is incorrect. L stands for low carbon.

304 L grade Low Carbon, typically 0.035% Max

304 grade Medium Carbon, typically 0.08% Max

Carbide precipitation

The weld areas with temperatures 930°F – 1470°F are often called carbide precipitation zone – in which Chromium (Cr) combines with Carbon (C) and precipitates chromium carbides at the grain boundaries significantly reducing corrosion resistance of steel in this zone. One of the ways to combat this phenomenon is to lower the carbon content in steel to decrease the carbide precipitation – 304L SS is an example of such steel; the “L” in 304L is for “Lower carbon” (.030% max vs. .080% max for 304 steel). Even more effective way against carbide precipitation is addition of Titanium (Ti) to the alloy to “stabilize it”. The carbon is more attracted to the Titanium (Ti) and therefore it leaves the chromium alone. To be a true “stabilized” grade the 321 steel has to have Titanium (Ti) content at least 5 times of Carbon’s (C). Reduced risk of corrosion in the HAZ is the main advantage of 321.

Fatigue strength

In dynamic applications, fatigue strength is also important to consider. And in this respect 321 Stainless Steel has a slight advantage over 304 Stainless Steel. Fatigue or endurance limits (strength in bending) of austenitic stainless steels in the annealed condition are about one-half the tensile strength.Typical tensile and endurance limits for these alloys (annealed) are presented in the table below:

Alloy	Typical Tensile Strength	Typical Endurance Limit
304L	68 ksi	34 ksi
304	70 ksi	35 ksi
321	76 ksi	38 ksi

Temperature Factors

Tempearture factors could be another factor to consider in some aplications. As we can see in the table below the temperature redaction factors are slightly higher for 321 than for 304L at most elevated temperatures:

Temperature °F	304L Factor	321 Factor
70	1.00	1.00
150	0.95	0.97
200	0.91	0.95
250	0.88	0.93
300	0.85	0.91
350	0.81	0.89
400	0.78	0.87
450	0.77	0.85
500	0.77	0.83
600	0.76	0.80
700	0.74	0.76
800	0.73	0.68
900	0.68	0.59
1000	0.63	0.65
1100	0.58	0.59
1200	0.53	0.53

 

  Source: https://tubingchina.com/Difference-Between-304-321.html

ASTM A249 TP347H: composition and mechanical properties

ASTM A249/ASME SA249 Standard Specification for Welded Austenitic Steel Boiler, Superheater, Heat-Exchanger, and Condenser Tubes

Standard: ASTM A249, ASME SA249

Material: TP347H, S34709

Chemistry Composition

C, % Si, % Mn, % P, % S, % Cr, % Ni, % Nb, % 0.04-0.10 1.00 max 2.00 max 0.045 max 0.030 max 17.0-19.0 9.0-13.0 8*C-1.1

Mechanical Properties

Tensile Strength , MPa Yield Strength, MPa Elongation, % Hardness, HRB 515 min 205 min 35 min 90 max