What is stainless steel?
It is an alloy with a 10.5%of chromium content by mass in it. Also known as inox or inox steel this content is created as a result of oxidation. It is mostly known because of its non-corrosive property. It is used in various applications like food handling, cutlery and aerospace etc. Unlike ordinary steel; stainless steel doesn’t rust, corrode or stain with water. But in conditions like high-salinity, low oxygen and poor air-circulation; it is not fully stain-proof. Stainless steel is mostly used where both the properties of corrosion resistance and steel are required.
There are many different items made from stainless steel to be used in various applications. Stainless steel hollow bars are one of them. They are tubes made from stainless that are available in wide ranges of grades and sizes.
There are two most common ranges of hollow bars i-e 304/304L and 316/316L.Both of them has different chemical and mechanical properties. Their sizes and specifications are also different.
Stainless steel hollow bars are low chromium-carbon-nickel alloy that has a very good strength and very resistive against corrosion. Their typical hardness is 175. Mostly known by their excellent resistive corrosion in an industrial atmosphere and marine areas, they are very good against chlorine attack and complex Sulphur compounds used in pulp and paper making industries. Its resistance to pitting corrosion can be increased by the addition of 2% to 3% of molybdenum in it. At elevated temperature, its creep resistance can be improved. As carbon content is low, there is very little risk of intergranular corrosion during welding. Intergranular corrosion happens due to the carbide precipitation. This thing reduces the need of post-weld annealing. Thus at elevated temperature, it shows good oxidation resistance.
Strength and hardness of stainless steel hollow bar can’t be achieved by thermal temperature but it can be hardened by cold working with a reduction in ductility subsequently. Nowadays due is available in the market with improved machinability i-e calcium is injected into it. It has improved the corrosion resistance a little bit but it has greatly improved the feeds and speeds of the material and its lifespan. This material is used in many areas such as paper, pulp marine, textile, architecture, aerospace, allied and transport industries.
Elevated temperature properties:
When it is heated up to 930-degree Celsius it shows really good corrosion resistance properties and shows intermediate properties when heated to 870-degree Celsius. As mentioned above less content of carbon in it reduces the susceptibility of intergranular corrosion when it is heated or slowing cooled down through a temperature range of 430 to 870-degree Celsius. However, its mechanical properties reduce when the temperature rises.
With low temperature, it shows really god properties like increased tensile. The yield strength of the material is also increased without any loss of toughness in the annealed condition. It can be used in extremely cold weather and at high altitudes and also for the storage of many liquefies gases with the help of the combination of increased toughness and strength at low temperatures.
Cold bending of the stainless steel hollow bar is not that difficult. But as the material has a high work hardening property so any cold working that has a chance of causing 15% of deformation must be followed by annealing.
Hot bending should also be performed followed by annealing in 900-degree centigrade to 1100 degree centigrade to restore the material optimum resistive properties of corrosion.
Welding is done by resistance welding and shielded fusion processes. These processes are followed by air toughness. The low carbon content allows it be welded easily without the loss of corrosion resistance properties.
You will not regret after spending money on stainless steel hollow bars as they will bring satisfaction to your need.