What are the characteristics of ship building steel plate?

December 14, 2021

Technical characteristics of the ship building steel plate

The following article shows the essential characteristics to determine the quality of a steel or stainless ship building steel plate: elongation, yield strength, tensile strength, hardness, toughness, aesthetics, and weight.

ship building steel plate

Production of the ship building steel plate

The most common production process of these steel and stainless steel plates uses the so-called coils. The coils are rolls obtained from the sheet produced by the casting of molten metal. In the first phase of production of the steel tube, the coils need to cut lengthwise.

It needs to form strips as wide as the development of the diameter of the steel tube. Later, these rolls passes into a series of rolls. Finally the tube carry welding to close the ends.

With this system it is possible to make both round and square and rectangular tubular steel plates. With the help of matrices, various types of ship building steel plate can be produced with the most varied geometric shapes.

Types of ship building steel plate according to UNI standards - Alloys

These steel plates, also known as carbon steel plates, are divided into two macro categories:

  • Mild steels: theyare very malleable and easily machinable steel tubes, they have a high mechanical resistance to traction and compression, as well as superior resilience
  • Hard steels:the main feature of these steel tubes is hardness, which however also makes them more prone to breakage. Hard steel plates are more difficult to machine than mild steel plates. They are ideal for heat treatments, such as nitriding or hardening.

How to produce these ships building steel plate on large scale?

The production of ship building steel plates requires compliance with particularly rigid and severe quality standards. These are essential to guarantee their quality and reliability. Whether they are round or square plates, that is to say with a circular or rectangular section.

They prove the bareness to withstand wear and the corrosive action of any external agents for a long time. In order to objectively and indisputably ascertain their quality, large plates have a function to severe tests and trials, such as:

  • X-ray examinations
  • Non-destructive tests
  • Eddy current
  • Penetrant liquids
  • Ultrasound

Main factor effecting quality of the ship building steel plate

In the event that all the checks successfully passes, appropriate certifications  issue. International bodies of recognized reputation and reliability provide these.

Obviously, the production and processing of large ship building steel plate depends - in their final result - on the quality of the materials used, namely steel.

With regard to the available processes, it is worth mentioning - among others - polishing, conical reduction, passivation, satin finishing, pickling and deboning of welds. Each procedure must follow with the utmost attention to the smallest details.  Only in this way, it is possible to ensure that the most advanced technology gives the best results.

Use of ship building steel plate

As far as the fields of application are concerned, large-sized 316 stainless steel plates are used in different contexts. Of course, it is the industrial sector that reigns supreme:

  • Firstly, from the petrochemical to the food industries
  • Secondly, from the pharmaceutical ones to the extractive ones
  • Thirdly, from the manufacturing to the chemical ones, the need for this type of plates, both square and round, is very high

It is therefore evident the ever-increasing importance assumed by large-sized ship building steel plate in the current economic context. What matters is that they comply with the Aisi regulations and offer the best possible reliability even after many years.

When is it better to choose ship building steel plate?

Steel plate, also called carbon steel, is preferable to stainless steel plate. It needs welding. Another reason why it is often preferable to stainless steel plate is the price, much lower.

Finally, it often chose for the higher quantity of finishes. It can provide in the processing and for its greater resistance. The industrial sectors in which these ship building steel plate are widely useful are:

  • Firstly, light carpentry
  • Secondly, medium / heavy carpentry
  • Thirdly, production of agricultural machinery
  • Fourthly, production of cabs for tractors and various machinery
  • Fifthly, production of various metal structures
  • Then, production of industrial sweepers
  • Furniture
  • Forestry machinery
  • Skillets
  • Railway sector, in particular for the production of window frames (also in aluminum), seat armrests or support handles

Steel tube bending: techniques and processes

Curving and calendaring are, together with welding and laser cutting, the main processes of the steel tube. The bending of the steel tube takes place with special machines called tube benders. The calendaring of the steel tube is carried out with machines called calendars.

The bending process takes place by passing a tube through 3 or 5 rollers. The calendaring of the ship building steel plate differs from the curvature in that it is possible to perform variable radii of curvature on the tube.

ship building steel plate 2021

Furthermore, the radius of curvature that can be imparted to the steel tube with the calendaring technique is much larger than that which can be obtained with its curvature through cold deformation.

Other processing of the steel tube

The tubes, tubular and profiles in steel and stainless steel can be processed in many different ways, depending on their final use. Many of these tube processes need simultaneously with both bending and calendaring of the steel tube:

Laser cutting - Machine that allows you to cut tube bars and perform drilling, countersunk drilling, inclined cuts, slots and markings.

The laser cutting has become one of the plate processing techniques indispensable: it allows making a cut to the ship building steel plate with absolute precision.

Welding - Process that allows you to assemble different plates. The final use of the curved steel tube almost always requires an assembly with other tubes or plates to allow for a finished product.

Milling - milling performs many processes such as holes or particular cuts on the steel plate through specific machinery called machining centers. Mainly used for processes that can usually be performed only after the tube has been bent.

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