Alloy 904L Tube Sheet Thickness: 240 MM External Diameter: 1385 MM

• Type: Alloy 904L Tube Sheet
• Material: 1.4539 (Alloy 904L/UNS N08904)
• Standard: ASME, etc
• Size: External Diameter: 1385 MM
• Thickness: 240 MM

What is Alloy 904L?

Alloy 904L is a low carbon high alloy austenitic stainless steel with good resistance to chloride pitting and crevice corrosion. It has also been shown to have good resistance to stress corrosion cracking in various environments. This alloy was developed for use in the chemical process industry, food processing, and the pharmaceutical industry where stress corrosion cracking is of concern.
It is used in the food processing industry (such as can ends), refrigeration equipment (gaskets), marine applications (vacuum pumps), chemical processing equipment (process vessels), medical instruments/equipment (catheters).
Fabrication of 904L
904L is a low carbon high alloy austenitic stainless steel. It is used for parts that require resistance to stress corrosion cracking, high temperature oxidation and high temperature/high pressure steam. 904L is also used for parts that require resistance to chloride stress corrosion cracking (SCC) in the presence of chlorides such as water vapor or hydrogen chloride gas, at temperatures up to about 400°C (752°F).
Applications of 904L
904L is used to make a variety of products, including:

• Food and beverage containers;
• Chemical equipment;
• Oil and gas pipes and equipment;
• Medical devices, such as artificial joints.

SS 904L Equivalent Grade

The datasheet below summarizes Rolex 904L stainless steel equivalent grade such as European EN (German DIN EN, British BS EN, French NF EN…), Chinese GB, ISO, Japanese JIS standard.

Datasheet and Specification of 904L

The following data sheet summarizes the chemical composition, properties, heat treatment and equivalent grade of 904L stainless steel (SS904L).

Chemical Composition of 904L

The following data sheet gives SS 904L stainless steel chemical composition.

Mechanical Properties of 904L

The following table lists Rolex 904L stainless steel (SS904L) mechanical properties such as yield strength, tensile strength, elongation and hardness.

Heat Treatment of 904L

Annealing: The recommended annealing temperatures for 904L wrought steel is 1095 °C (2000 °F).

Corrosion resistance of 904L stainless steel

Since the carbon content of 904L is very low (max. 0.020%), there is no carbide precipitation under general heat treatment and welding. This eliminates the risk of intergranular corrosion that occurs after general heat treatment and welding. Due to the high chromium-nickel-molybdenum content and the addition of copper elements, 904L can be passivated even in reducing environments such as sulfuric acid and formic acid. The high nickel content gives it a low corrosion rate even in the active state. In the concentration range of 0-98% pure sulfuric acid, 904L can be used at temperatures up to 40 degrees Celsius. In pure phosphoric acid in the concentration range of 0-85%, its corrosion resistance is very good. In industrial phosphoric acid produced by the wet process, impurities have a strong influence on the corrosion resistance. In all kinds of phosphoric acid, 904L corrosion resistance is better than ordinary stainless steel. In strongly oxidizing nitric acid, 904L has lower corrosion resistance compared to highly alloyed steel grades without molybdenum. In hydrochloric acid, the use of 904L is limited to a lower concentration of 1-2%. In this concentration range. 904L has better corrosion resistance than conventional stainless steels. 904L steel has a high resistance to pitting corrosion. Its resistance to crevice corrosion is also good in chloride solutions. 904L’s high nickel content reduces the rate of corrosion at pits and crevices. Ordinary austenitic stainless steels may be sensitive to stress corrosion in a chloride-rich environment at temperatures above 60 degrees C. This sensitization can be reduced by increasing the nickel content of the stainless steel. Due to the high nickel content, 904L has a high resistance to stress corrosion rupture in chloride solutions, concentrated hydroxide solutions and hydrogen sulfide-rich environments.

Processing performance of 904L

Welding performance of 904L

As with general stainless steel, 904L can be welded using a variety of welding methods. The most commonly used welding method for manual arc welding or inert gas shielded welding, welding rod or wire metal based on the composition of the base metal material and higher purity, molybdenum content requirements than the base material. Preheating is generally not necessary before welding, but in cold outdoor work, to avoid condensation of water vapor, the joint or the adjacent area can be uniformly heated. Note that the local temperature should not exceed 100 ℃, so as not to lead to carbon agglomeration, causing intergranular corrosion. Welding should use a small linear energy, continuous and fast welding rate. After welding generally do not need heat treatment, if heat treatment, must be heated to 1100-1150 ℃ after rapid cooling.

Matching welding consumables: welding rod (E385-16/17), welding wire (ER385).

Machinability of 904L
904L machining characteristics similar to other austenitic stainless steel, the process has a tendency to sticky tool and work hardening. Must use positive front angle carbide tools, sulfide and chlorinated oil as cutting coolant, equipment and process should be to reduce the premise of machining hardening. Slow cutting speed and tool feed should be avoided in the cutting process.

What is a tube sheet?

Tube sheet is a plate, sheet or bulkhead which is perforated with a pattern of holes. It serves as an attachment point for the straight tubes or U-tubes which pass through it into the tube sheet. A tube sheet is usually made from a round flat piece of plate,sheet with holes drilled to accept the tubes or pipes in a accurate location and pattern relative to one another. The tube sheets are used to support and isolate tubes in heat exchangers and boilers or to support filter elements.
Tube sheets are used to support and isolate tubes in heat exchangers and boilers. They are also used to support filter elements.
It serves as an attachment point for the straight tubes or U-tubes which pass through it into the tube sheet.
Tube sheets are used to support and isolate tubes in heat exchangers and boilers. A tube sheet is a flat plate, sheet or other similar structure that serves as an attachment point for the straight tubes or U-tubes which pass through it into the tube sheet.
Tube sheets provide attachment points for all of the straight tubes that pass through it, as well as any U-tubes which may be present.

China Tube Sheets Manufacturer www.ugsteelmill.com offers Alloy 904L Tube Sheet Thickness: 240 MM External Diameter: 1385 MM.