310 Stainless Steel Pipe Suppliers: Quality, Grades and Pricing

Procuring reliable 310 stainless steel pipe suppliers requires more diligence than most procurement activities. This is due to customer demands and the challenges of fabricating 310 stainless steel pipes. The 310 stainless steel pipe is strong enough to withstand extremely high temperatures for prolonged periods of time, far beyond the temperatures and lengths of time that most other metals can withstand. This high level of performance paired with the safety threats that come with faulty heat resistant pipe lining and equipment explains why there is such a high priority placed on the quality of procurement of 310 stainless steel pipe.

The sourcing of 310 stainless steel pipe becomes a real challenge to procurement specialists because once the pipe is purchased, there is no way to decipher 310 stainless steel pipe from 310 stainless steel pipe that is safe for welding. Considering that 310 stainless steel pipes and 310 stainless steel pipes that are safe for welding are chemically the same, the only way to decipher the two is if the pipe is subjected to heat, at which point it will fail to weld, or if the pipe is welded. The Welds will fail. Because of the challenge posed by sourcing 310 stainless steel pipe, a great deal of additional planning is required to ensure that a project does not have to be shut down.

What Makes Grade 310 Different From Ordinary Stainless?

Compared to other common stainless steels, Grade 310 is made with roughly 25% chromium and 20% nickel, making it somewhat of a high-performance stainless steel. At these levels of chromium, the alloy forms a very strong, tenacious oxide layer which does not spall (flake or peel off of the surface) even when common stainless steels begin to fail. Continuous exposure up to about 1150°C, with intermittent exposure to lower temperatures (due to the thermally induced stress), is allowed. 

The presence of 20% nickel is important for many reasons as well. This level of nickel ensures that the structure stays fully austenitic over a large range of temperatures. This prevents steels from becoming brittle from long-term exposure to heat. Grade 310 also has good resistance to two types of slow, destructive attacks, sulfidation and carburization which occur inside furnaces and processing equipment and attack equipment from the inside out. Because it welds without preheat, and because it forms easily in the annealed state, it is appreciated by fabricators. 

When welding Grade 310, standard 310 alloys have better creep strength at high temperature. However, welding 310S variants results in less precipitation of Cr carbides due to the 0.08% carbon content (maximum), which is a positive effect on corrosion in the heat affected zone. Neither grade should be selected over the other if it means a potential waste of money or service life.

How to Evaluate a Supplier Before a Purchase 

The Indian market has companies offering the same level of quality at vastly different prices and order volume is often correlated to origin, certification, and whether or not the seller actually touched the material. Any reputable Stainless Steel Heat Exchanger Tube Manufacturer in India would take the time to show you their mill sources, their testing labs, and their material stock before quoting prices because they understand that a customer that is fully informed is more likely to be a customer for life.

Actual Certification That Refers to the Metal

An EN 10204 3.1 certificate should link a specific heat number to a documented chemical analysis and mechanical test demonstration, and that heat number should be present on the pipe. A certificate that cannot be linked to any identifiable marks is just a piece of paper. Suppliers that provide documentation in advance, welcome third party audits, and are not opposed to verifying material at dispatch, are confident in their position. Lack of such confidence is the biggest warning sign.

Stock Depth and Manufacturing Capability

When asking for size availability across seamless and welded forms, in standardized and custom lengths,; genuine stockists have the information readily on hand. Traders have to call for the information. While sourcing through a trader isn’t incorrect, the customer would lose visibility on the origin of the shipment and would have to take the trader's lead time and margin. Suppliers who offer in-house cutting, pickling, polishing, and hydro testing, make a real difference by reducing the work a customer would have to do post delivery.

Technical Understanding of Your Application 

A supplier is concerned about how their offered grade would perform against your operating temperature, cycling, and process conditions. Another supplier would offer a quote in under thirty seconds for a particular size. When your requirements are close to the grade line, this distinction of grade would make a difference.

Where This Grade Earns Its Keep in Indian Industry

Within Indian Industry, 310 Grade is used in cement plants for construction of kiln, burner and cooler pipes which face abrasion and high temperatures caused by dust. This Grade is used by steel makers for construction of annealing boxes and tubes, and muffle furnaces, as well as for the transportation of components through the reheating zones. In petrochemical refineries, this Grade is used to construct flare tips, thermowells, and hardware for the reformer. Fertilizer, sugar, thermal power generation, glass manufacturing, etc. industries use this grade in large volumes.

Heat exchanger bundles often incorporate tubing of higher grade material. Failure of a single tube in a bundle can be a very costly repair, especially if the fluid is high temperature process steam or hot flue gas. Excellent combination of oxidation resistance and thermal cycling strength means higher grades are used to eliminate frequent replacements of lower grades.

Understanding Pricing, Lead Times and Total Cost

Pricing for 310 reflects changes in global nickel and chromium prices. A quote held for one calendar month may be optimistic. Given the alloy content, higher than 304 and 316, this grade is significantly more expensive.

What Drives the Number on Your Quotation

Seamless tubing is more expensive than welded tubing, due to a longer, more difficult manufacturing process and lower yields. Smaller diameter, thinner wall tubing costs more than larger, heavier diameter tubing. Higher tolerances, special surface finishes, solution annealing, and/or extended testing also add to the final cost. Small quantity orders also add to the final cost. Cutting a full length of tubing leaves a supplier with a remnant that is unsold for a longer period of time.

Lead Times You Can Plan Around

Material held in stock is shipped in a short period of time. Domestic or imported mill orders are between 12 and 20 weeks, depending on the source and current orders. Suppliers offering mill-fresh imported tubing in a month are likely offering existing stock that is satisfactory or questionable in origin, depending on the circumstances.

Developing a Supplier Relationship Built to Sustain Unexpected Market Demand

Assessing a supplier when your equipment is malfunctioning is a bit too late. Go see the supplier’s warehouse and check the supplier’s material organization and storage methods. See if the supplier will allow you to view a certificate and compare that certificate to the pipe that he is providing. Take a small test order and see how the supplier performs in terms of documentation, packaging, and communication. Suppliers who welcome this type of order review typically have a steady customer base as opposed to one-time customers. 

Long-term relationships also provide you designation to preferred customer status. In such relationships, customers are notified of longer lead times prior to a competitor resulting in the loss of an order. The actual time that the order is shipped is of little consequence in such relationships. When engineers and purchasing agents evaluate procured materials, traceability, and honest delivery, Eramets Steel Alloys is a strong sourcing option.