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.

 

SAE 904L: Chemical Composition, Propertes and Applications

SAE 904L is a non-stabilized austenitic stainless steel alloy that is known for its high corrosion resistance properties. It contains high levels of nickel and molybdenum, which give it excellent resistance to a wide range of corrosive environments. In this article, we will discuss the properties of SAE 904L stainless steel in detail.

Equivalent grades include:

• EN 1.4539 (X1NiCrMoCuN25-20-5)
• UNS N08904
• AISI 904L
• DIN 1.4539
• ASTM A182 F904L
• JIS SUS 890L
• AFNOR Z2 NCDU 25-20

Chemical Composition:

The chemical composition of SAE 904L stainless steel includes high levels of nickel, chromium, and molybdenum. It also contains copper, which enhances its resistance to acids. The low carbon content in the alloy minimizes the risk of intergranular corrosion.

The chemical composition of SAE 904L stainless steel typically includes:

• Carbon (C): Maximum of 0.020%
• Silicon (Si): Maximum of 1.00%
• Manganese (Mn): Maximum of 2.00%
• Phosphorus (P): Maximum of 0.045%
• Sulfur (S): Maximum of 0.035%
• Chromium (Cr): 19.0% - 23.0%
• Nickel (Ni): 23.0% - 28.0%
• Molybdenum (Mo): 4.0% - 5.0%
• Copper (Cu): 1.0% - 2.0%
• Nitrogen (N): Maximum of 0.10%
• Iron (Fe): Balance

Corrosion Resistance: SAE 904L stainless steel is known for its excellent corrosion resistance properties. It is highly resistant to a wide range of corrosive environments, including sulfuric acid, hydrochloric acid, and phosphoric acid solutions. It also has good resistance to pitting and crevice corrosion. The high nickel and molybdenum content in the alloy provide it with excellent resistance to stress corrosion cracking.

Mechanical Properties:

SAE 904L stainless steel has good strength and ductility. Its high tensile strength and yield strength provide the necessary strength for structural applications. The alloy also has good elongation, which means it can undergo plastic deformation without cracking or breaking. The low carbon content in the alloy minimizes the risk of sensitization and intergranular corrosion. The alloy's high nickel and molybdenum content provide it with excellent toughness and resistance to stress corrosion cracking.

The mechanical properties of SAE 904L stainless steel typically include:

• Tensile strength: 490 MPa (71 ksi) minimum
• Yield strength: 220 MPa (32 ksi) minimum
• Elongation: 35% minimum
• Hardness: Brinell 70 maximum; Rockwell B 90 maximum

Physical Properties:

SAE 904L stainless steel has a density of 7.98 g/cm³ (0.289 lb/in³) and a melting point of 1350°C (2460°F). It has a thermal conductivity of 13.1 W/m·K (9.03 BTU/hr·ft·°F) and a specific heat capacity of 500 J/kg·K (0.12 BTU/lb·°F).

Applications:

SAE 904L stainless steel is commonly used in applications that require high corrosion resistance, such as in the chemical processing, oil and gas, and pulp and paper industries. It is also used in medical and laboratory equipment due to its high corrosion resistance and bright finish. The alloy is also used in heat exchangers, condensers, and other equipment that requires high resistance to corrosive environments.

In conclusion, SAE 904L stainless steel is a highly versatile alloy with excellent corrosion resistance properties. Its high nickel and molybdenum content provide it with excellent resistance to a wide range of corrosive environments. The alloy's good mechanical and physical properties make it suitable for use in a wide range of applications, including chemical processing, oil and gas, and medical equipment.

References:

1.     "904L Datasheet" (PDF). Atlas Steels.

2.     ^ "904L Datasheet" (PDF). Rolled Alloys.

3.     ^ "904L Datasheet" (PDF). ATI Metals.

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.

 

How to improve the bonding force of electroless nickel plating on stainless steel

Electroless nickel plating of stainless steel parts (drive shafts, meshing parts, moving parts, etc.) can improve the uniformity and self-lubricity of the plating, which is better than chromium plating. However, electroless nickel plating on stainless steel often results in unsatisfactory bonding between the plating layer and the substrate due to poor pretreatment, which has become an urgent problem in actual production.

The original process: mechanical polishing → organic solvent degreasing →chemical degreasing → hot water washing → electrochemical degreasing → hot water washing → cold water washing→ 0%HCl → cold water washing→ 20%HCl(50℃) → cold water washing → flash plating Nickel → electroless nickel plating.

Disadvantages of the original process: the effect of using HCL alone to remove the oxide scale is not good; the flash nickel plating of complicated shapes affects the uniformity of electroless nickel plating due to poor coverage; the longer process may cause the fresh surface of stainless steel to be re-oxidized. Film; flash nickel plating solution is easy to pollute chemical nickel plating solution, etc. To this end, someone improved the process.

Improved process flow: the polishing and degreasing process is the same as the original process → mixed acid removal film (25%HCl+8%HNO3+10%HF) → cold water washing → activation (10%HCl+5%NH4F, 60℃) → hot water washing → Electroless Nickel.

The advantages of the improved process:

1.     Use mixed acid to remove the insoluble FeCrO4 oxide film, Si, SiO2 on the surface of the stainless steel, and enhance the chemical activity of the surface of the substrate，

2.     The process is simplified to avoid the fresh surface of the stainless steel from being re-oxidized，

3.     The preheating process of the substrate is increased , Eliminate the stress caused by the temperature difference between the plating layer and the substrate. Therefore, the electroless nickel plating has a good bonding force with the substrate, and the plating speed is fast.

Source: tubingchina.com

Difference Between Stainless Steel 321 and 347

ASTM A213 321 321H 347 347H Chemical Composition:

Grade	321	321H	347	347H
UNS Designation	S32100	S32109	S34700	S34709
Carbon (C) Max.	0.08	0.04–0.10	0.08	0.04-0.10
Manganese (Mn) Max.	2.00	2.00	2.00	2.00
Phosphorous (P) Max.	0.045	0.045	0.04	0.04
Sulphur (S) Max.	0.03	0.03	0.03	0.03
Silicon (Si) Max.	1.00	1.00	0.75	0.74
Chromium (Cr)	17.0–20.0	17.0–20.0	17.0–20.0	17.0–20.0
Nickel (Ni)	9.0–12.0	9.0–12.0	9.0–13.0	9.0–13.0
Molybdenum (Mo)	–	–	–	–
Nitrogen (N)	–	–	–	–
Iron (Fe)	Bal.	Bal.	Bal.	Bal.
Other Elements	Ti=5(C+N) to 0.70%	Ti=4(C+N) to 0.70%	Cb+Ta=10xC-1.0	Cb+Ta=10xC-1.0

A limitation with 321 is that titanium does not transfer well across a high temperature arc, so is not recommended as a welding consumable. In this case grade 347 is preferred – the niobium performs the same carbide stabilisation task but can be transferred across a welding arc. Grade 347 is therefore the standard consumable for welding 321. Grade 347 is only occasionally used as parent plate material.

Like other austenitic grades, 321 and 347 have excellent forming and welding characteristics, are readily brake or roll formed and have outstanding welding characteristics. Post-weld annealing is not required. They also have excellent toughness, even down to cryogenic temperatures. Grade 321 does not polish well, so is not recommended for decorative applications.

TP321 Stainless Steel Tubes

Features:

TP321 is a stabilized stainless steel that offers as its main advantage an excellent resistance to intergranular corrosion following exposure to temperature in the chromium carbide precipitation range from 800 °F to 1500°F (427°C to 816°C). Alloy 321 stainless steel tubing is stabilized against chromium carbide formation by the addition of titanium.

TP347H Stainless Steel Tube:

Features:
It is a stable austenitic heat-strength steel. It has good heat strength and resistance to intergranular corrosion, good welding performance, and good corrosion resistance in alkali, seawater and various acids.347H and 347HFG in higher elevated temperature allowable stresses for these stabilized alloys for ASME Boiler and Pressure Vessel Code applications.

Application:
Heat exchangers for large boiler superheater tubes, reheater tubes, steam lines and petrochemicals. The allowable oxidation temperature in boiler tubes is 750 °C.