ASTM SS 410 Seamless Pipes & Tubes

Useful Information:

Grade 410 is the basic martensitic stainless steel; like most non-stainless steels it can be hardened by a “quench-and-temper” heat treatment. It contains a minimum of 11.5 per cent chromium, just sufficient to give corrosion resistance properties. It achieves maximum corrosion resistance when it has been hardened and tempered and then polished. Grade 410 is a general purpose grade often supplied in the hardened, but still machinable condition, for applications where high strength and moderate heat and corrosion resistance are required.

Martensitic stainless steels are optimised for high hardness, and other properties are to some degree compromised. Fabrication must be by methods that allow for poor weldability and usually the need for a final heat treatment. Corrosion resistance of the martensitic grades is lower than that of the common austenitic grades, and their useful operating temperature range is limited by their loss of ductility at sub-zero temperatures and loss of strength by over-tempering at elevated temperatures.

Composition of 410 Stainless Steel Pipes and Tubes
Typical compositional ranges for grade 410 stainless steels are given in table 1.

Table 1. Composition ranges for 410 grade stainless steel

Mechanical Properties of 410 Stainless Steel Pipes and Tubes
Typical mechanical properties for grade 410 stainless steels are given in table 2.

Table 2. Mechanical properties of 410 grade stainless steel

Physical Properties of 410 Stainless Steel Pipes and Tubes
Typical physical properties for annealed grade 410 stainless steels are given in table 3.

Table 3. Physical properties of 410 grade stainless steel in the annealed condition

Grade Specification Comparison of 410 Stainless Steel Pipes and Tubes
Approximate grade comparisons for 410 stainless steels are given in table 4.

Table 4. Grade specifications for 410 grade stainless steel

Corrosion Resistance of 410 Stainless Steel Pipes and Tubes
410 resists dry atmosphere, fresh water, mild alkalies and acids, food, steam and hot gases. Must be hardened for maximum heat and corrosion resistance. Performance is best with a smooth surface finish. Less corrosion resistant than the austenitic grades and also less than 17% chromium ferritic alloys such as Grade 430.

Seamless Pipe benefits

1) Pressure Ratings

The greatest advantage of seamless steel pipes is their increased ability to withstand pressure. The weakest point in a welded steel pipe is the welded seam. But because a seamless steel pipe has not been welded, it doesn’t have that seam, making it equally strong around the entire circumference of the pipe.

It is also much easier to determine pressure calculations without being required to take weld quality into consideration. Although seamless pipe can sometimes be more expensive than welded pipe, this increased ability to withstand pressure allows you to use pipes that are thinner and lighter, which can help cut down on expenses.

2) Uniformity of Shape Because welded seam pipe is wrapped around another form before it is welded, and because welding adds heat, stress and other extraneous variables to the forming process, it can never be as round as seamless steel pipe.

Seamless steel pipe is a continuous extrusion of the alloy, meaning that it will have a round cross section that you can count on, which is helpful when you’re installing pipes or adding fittings.

3) Strength Under Loads Seamless steel pipe can sometimes be more expensive than other forms of steel pipe, but it’s also more reliable. This is because it has greater strength under loading. Empty pipe must always support its own weight, but when a pipe is filled with material–or under load–it must also support that weight as well. Pipe failures and leaks in welded pipes usually occur at the welded seam. But because seamless pipe doesn’t have that seam, it isn’t subject to those failures.

4) Production Processes Seamless pipes are manufactured using different procedures, depending on the diameter or the ratio of diameter to wall thickness. The normal raw material is a round spool section preheated in a rotary furnace, or for larger diameters a hollow section preshaped in a perforation press, which is then prerolled in a rotary rolling mill. In the manufacture of longitudinally welded pipes, either individual steel plates or coils are used as raw material. The pipes are produced in a series of different, sequenced process stages, including cold forming, welding, heat treatment, calibration and non-destructive testing.

5) Pipe Lengths and Quantities When manufacturing seamless pipes, the length manufactured depends on the weight per metre or per rod. Thus up to NB 100, pipe lengths of a maximum 13 m, and up to NB 200 pipe lengths of a maximum of around 4 m can be produced. The minimum purchase quantity is determined by the size of the production batch of around 1t.