Classification of Steel Products produced in Steel Plants...

Classification of Steel Products produced in Steel Plants Steel products in general are classified as (i) castings, (ii) forged products, (iii) stamped products, (iv) bright products, (v) cold formed products, (vi) welded sections, (vii) wire and wire products, (viii) pipes, tubes, hollow sections and hollow bars, and (ix) powder metallurgy products. Steel products produced in steel plants are classified as per (i) stage of manufacture of the product, (ii) shape and dimensions of the product, and (iii) the product appearance. As per the stage of manufacture, the range of steel products produced in the steel plants are usually grouped into three main categories (Fig 1) namely (i) crude steel products, (ii) semi-finished steel products, and (iii) finished rolled steel products. Finished rolled steel products can be (i) hot rolled products, (ii) cold rolled products, and (iii) coated products.  Fig 1 Categories of steel products Crude steel products Crude steel products are either in the liquid state or in solid state. Liquid steel is normally used for the production steel castings. Crude steel in solid form was earlier considered as steel ingots which are produced by pouring liquid steel into iron moulds of a shape appropriate to the subsequent processing into semi-finished or finished steel products normally by hot rolling or forging. The shape of steel ingots usually resembles a truncated pyramid or truncated cone with the side surfaces may be corrugated and the corners more or less rounded. Steel ingots may be dressed and/or hot scarfed or cropped depending on the subsequent conversion requirements. Steel ingots can be distinguished based on their cross sections as (i) having a cross-section which can be square, rectangular (of width less than twice the thickness), polygonal, round, oval or shaped according to the profile to be rolled, (ii)...

Pipe and Tubular Products of Steel...

Pipe and Tubular Products of Steel The term pipe and tubular product of steel is the used to cover all hollow products of steel. These products are normally produced in cylindrical shape. However, they are frequently altered by different processing methods to produce square, oval, rectangular, and other symmetrical forms. Pipe and tubular products have a large number of applications, but they are most commonly used for conveying of fluids and as structural members. Steel pipe and tubular products are normally produced from wrought carbon (C) or alloy constructional steels and are usually designated by the terms pipe, specialty tubing, and oil country tubular goods (OCTG) etc. Pipes and tubular products have an outside dimension, an inside dimension and the wall thickness as shown in Fig 1. Fig 1 Dimensions of pipe and tubular products The steel pipe and tubular products are usually classified broadly as (i) pipe, and (ii) tube. The application of the terms pipe and tube is not always consistent. The term pipe is normally used to describe cylindrical products made to standard combinations of outside diameter and wall thickness. The main difference between a pipe and a tube is the way the diameter of the pipe or tube is designated. Pipe is normally designated by a “Nominal Pipe Size” based upon the ID (inside diameter) of the most common wall thickness while the tube is designated by the measured OD (outside diameter). As an example a 20 mm steel pipe with 4 mm thickness has an OD of 28 mm while a 20 mm steel tube has an OD of 20mm.  The two broad classifications of steel pipe and tubular products are subdivided into several named use groups. As an example, the term tube covers three such groups namely (i)...