Facebook Instagram Youtube Twitter

What is Hardness of Wrought Iron – Definition

Brinell hardness of wrought iron is approximately 100 MPa. In materials science, hardness is the ability to withstand surface indentation (localized plastic deformation) and scratching. Hardness of Wrought Iron
wrought iron
Many products described as wrought iron, such as guard rails, garden furniture and gates, are actually made of mild steel.

Wrought iron is an iron alloy with very low carbon content (less than 0.08%) with respect to cast iron (2.1% to 4%). The microstructure of wrought iron shows dark slag inclusions in ferrite. It is soft, ductile, fibrous variety that is produced from a semifused mass of relatively pure iron globules partially surrounded by slag. It usually contains less than 0.1 percent carbon and 1 or 2 percent slag. Wrought iron is magnetic, corrosion-resistant and easily welded. It has high elasticity and tensile strength. It can be heated and reheated and worked into various shapes. Wrought iron is no longer produced on a commercial scale. The modern functional equivalent of wrought iron is mild steel, also called low-carbon steel. Many products described as wrought iron, such as guard rails, garden furniture and gates, are actually made of mild steel. For example, the Eiffel Tower is a wrought-iron lattice tower.

Hardness of Wrought Iron

Brinell hardness of wrought iron is approximately 100 MPa.

Brinell hardness numberIn materials science, hardness is the ability to withstand surface indentation (localized plastic deformation) and scratching. Hardness is probably the most poorly defined material property because it may indicate resistance to scratching, resistance to abrasion, resistance to indentation or even resistance to shaping or localized plastic deformation. Hardness is important from an engineering standpoint because resistance to wear by either friction or erosion by steam, oil, and water generally increases with hardness.

Brinell hardness test is one of indentation hardness tests, that has been developed for hardness testing. In Brinell tests, a hard, spherical indenter is forced under a specific load into the surface of the metal to be tested. The typical test uses a 10 mm (0.39 in) diameter  hardened steel ball as an indenter with a 3,000 kgf (29.42 kN; 6,614 lbf) force. The load is maintained constant for a specified time (between 10 and 30 s). For softer materials, a smaller force is used; for harder materials, a tungsten carbide ball is substituted for the steel ball.

The test provides numerical results to quantify the hardness of a material, which is expressed by the Brinell hardness numberHB. The Brinell hardness number is designated by the most commonly used test standards (ASTM E10-14[2] and ISO 6506–1:2005) as HBW (H from hardness, B from brinell and W from the material of the indenter, tungsten (wolfram) carbide). In former standards HB or HBS were used to refer to measurements made with steel indenters.

The Brinell hardness number (HB) is the load divided by the surface area of the indentation. The diameter of the impression is measured with a microscope with a superimposed scale. The Brinell hardness number is computed from the equation:

Brinell hardness test

There are a variety of  test methods in common use (e.g. Brinell, Knoop, Vickers and Rockwell). There are tables that are available correlating the hardness numbers from the different test methods where correlation is applicable. In all scales, a high hardness number represents a hard metal.

References:
Materials Science:

U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 1 and 2. January 1993.
U.S. Department of Energy, Material Science. DOE Fundamentals Handbook, Volume 2 and 2. January 1993.
William D. Callister, David G. Rethwisch. Materials Science and Engineering: An Introduction 9th Edition, Wiley; 9 edition (December 4, 2013), ISBN-13: 978-1118324578.
Eberhart, Mark (2003). Why Things Break: Understanding the World by the Way It Comes Apart. Harmony. ISBN 978-1-4000-4760-4.
Gaskell, David R. (1995). Introduction to the Thermodynamics of Materials (4th ed.). Taylor and Francis Publishing. ISBN 978-1-56032-992-3.
González-Viñas, W. & Mancini, H.L. (2004). An Introduction to Materials Science. Princeton University Press. ISBN 978-0-691-07097-1.
Ashby, Michael; Hugh Shercliff; David Cebon (2007). Materials: engineering, science, processing and design (1st ed.). Butterworth-Heinemann. ISBN 978-0-7506-8391-3.
J. R. Lamarsh, A. J. Baratta, Introduction to Nuclear Engineering, 3d ed., Prentice-Hall, 2001, ISBN: 0-201-82498-1.

See above:
Wrought Iron

We hope, this article, Hardness of Wrought Iron, helps you. If so, give us a like in the sidebar. Main purpose of this website is to help the public to learn some interesting and important information about materials and their properties.