Stainless Steel 310S Round Bar: An Invaluable Resource for Engineers and Procurement Experts

Grade 310S might not be a star, but it is in almost every plant that processes very corrosive chemicals that operate at very high temperatures. Engineers spend lots of time determining appropriate materials for various furnace components, heat exchangers and high-temperatures structural components. Engineers learn to understand and appreciate the reputation of various materials.

Thermal Advantages

Most grades of stainless steel will begin to lose their structural integrity within the 700°C to the 900°C range. Because it contains 26% chromium and 21% nickel, 310S will withstand multiple alloys at higher temperatures. This grade of stainless steel is particularly effective at resisting oxidation when subjected to thermal stress.

The ‘S’ of 310S denotes that it has a lower carbon ceiling than the standard grade of 310. Because of the lower carbon content, the risk of intergranular corrosion and chromium carbide precipitation is reduced. This is especially important for stainless steels that will be heavily fabricated.

Here are the Key Properties

High Strength

Service Temperatures of 1150°C

Excellent Fabrication

Corrosion Resistant

These properties help to justify the global acceptance of Stainless Steel 310S Round Bar in power generation, petrochemical and aerospace projects.

Where This Grade Gets Specified — and Why

The Procurement teams from the sectors listed below know all about the Stainless Steel 310S Round Bar as it has specific applications.

Petrochemical and Refining — Radiant tubes and reformer and furnace components that experience extreme temperature cycling.

Power Generation — The internal components of a boiler and a heat exchanger that have a constant temperature differential.

Aerospace — Lightweight structural components that have oxidization stability and resistance at high altitudes and at varying atmospheric conditions.

Pharmaceutical Manufacturing — In environments where surface integrity of the metal and corrosion resistance are of major concern, and where the state of the surface is a matter of regulation.

Pulp and Paper — Digester equipment exposed to sulfur and various other corrosive and acid environments.

Food Processing — Equipment that contains a surface free of corrosion and undesirable contaminants that is exposed to high temperatures during the sterilization and cooking process.

If your processes involve the use of 310S at above 800°C and are dealing with corrosive media, then 310S is a clear candidate for your processes.

What to Check Before You Place an Order

A specific grade number does not make it any easier to procure the correct bar stock. Experienced procurement teams verify the following prior to the order.

Compliance Standards

Bar stock must meet ASTM A276 or ASTM A479 standards. A good vendor will provide a Mill Test Certificate complying with EN 10204, 3.1 or 3.2, and will ideally provide a certificate for testing done in a NABL accredited laboratory.

Size Range Availability

A good supplier will provide Stainless Steel 310S Round Bar in diameters from 1/16” to 26”, along with a variety of other profiles (hex, flat, square and rectangular). Other dimensions can be supplied, but be sure to confirm the ability to provide bars of the required length.

Surface Finish Options

The selection of a surface finish will impact the ease of machining the part and the final dimensions. The most common surface finishes are described below.

Cold Drawn and Ground – When the bar is drawn and then ground, this provides a surface finish and bar with the tightest tolerances.

Bright Drawn (BD) – This finish has a nice appearance and can be used for a final or exposed surface.

Hot Rolled Annealed and Pickled (HRAP) – A suitable surface finish for a bar used in a non-critical or structural application.

Peeled and Polished – A finish that provides a surface clear of oxides that is suitable for a critical application.

Tolerance Classes

Interchangeability of components is determined by the tolerances specified. Most engineering applications will be covered by ISO tolerances h8 to h11, so verify the tolerance class prior to your order.

A Note on Welding and Fabrication

The reasonable weldability of 310S provides advantages on assemblies with complicated fabrications. The following may be useful:

To weld sections of the same composition use ER310 filler metal.

Control the interpass temperature as distortions may occur in long sections.

If post weld critical service applications are considered, further treatment may be required.

Do not weld in a contaminated atmosphere. The alloy’s corrosion resistance is lost if a clean chromium oxide layer cannot be formed.

Selecting a Supplier

Stainless Steel 310S Round Bar will not be of any use with poor specifications to the supplier. The supplier must maintain stock on demand, and should be able to provide a variety of services from cutting to polishing, and provide certified mill documents.

Virwadia Metal Corporation, located in Chennai, carries a good stock of round, hexagonal, flat, and square profile bars and also provides direct delivery service to Hosur, Coimbatore, Salem, and Erode in Tamil Nadu. Their stock is also supported by certifications as per EN 10204 3.1 and NABL.