Carbon Seamless Tube Vs Stainless Seamless Tube

Changsha China
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Steel Fabrication
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Steel Pipes

The difference between carbon seamless tube and stainless seamless tube mainly refers to the difference in design rules between carbon steel and stainless steel, which means that the design rules of these two types of steel cannot be used in common. These differences are summarized as follows:

Carbon steel

1. Ordinary steel is carbon steel, that is, iron-carbon alloy. According to the level of carbon content, it is divided into low-carbon steel seamless pipes (to be called wrought iron), medium-carbon steel seamless tubes and cast iron. Generally, those with a carbon content of less than 0.2% are called low-carbon steel seamless tubes (mild seamless tube), commonly known as wrought iron or pure iron; those with a content of 0.2-1.7% are called steel; those with a content of more than 1.7% are called pig iron.

2. It is usually used on metal parts that require strength, hardness and wear resistance, such as cutting tools, steel cables, piano wires, springs and knives, etc. After being processed, the parts usually need to be processed and tempered. The higher the carbon content of steel, the higher its hardness, strength and wear resistance after heat treatment. Carbon steel is divided into high-carbon steel, medium-carbon steel and low-carbon steel; according to its characteristics, high-carbon steel is hard and brittle, and low-carbon steel is soft and ductile.

Stainless steel

1. There are many types of stainless steel seamless tubes, which refer to alloy steels with Cr content greater than or equal to 13% and stainless steel in the atmosphere. There are austenitic stainless steel seamless tubes, ferritic stainless steel seamless tubes, martensitic stainless steel seamless tubes and so on. Stainless steel seamless tubes generally do not have magnetism, but they are not completely correct. Austenitic ones have no magnetism, but ferrite ones have, but they are relatively weak. Different stainless steel seamless tubes have different corrosion resistance and different corrosion resistance to different media.

2. In terms of corrosion resistance. In practical applications, stainless steel seamless tubes have excellent various properties that cannot be replaced by other steel types. For example, some high-temperature resistant stainless steel seamless tubes, and the excellent surface characteristics of stainless steel seamless tubes are widely used for decoration. Materials, as well as the excellent mechanical properties of stainless steel seamless tubes, make it used in various manufacturing industries.


The design rules for stainless steel cannot be used for carbon steel because there are 3 fundamental differences between stainless steel and carbon steel:

1. Stainless steel undergoes work hardening during cold working, for example, it has anisotropy during bending, that is, the transverse and longitudinal properties are different. The increased strength by cold working can be used, but if the bending area is small compared to the total area and this increase is ignored, the increased strength can increase the safety factor to a certain extent.

2. The shape of the stress/strain curve is different. The elastic limit of stainless steel is about 50% of the yield stress. As far as the minimum value specified in the standard is concerned, the yield stress value is lower than that of medium carbon steel.

3. Stainless steel has no yield point, usually expressed as ó0.2, the yield stress is considered to be an equivalent value.