Shot Peeners’ Magic Steel MANGALLOY

Author:  Dr. David Kirk | Coventry University
Source:  The Shot Peener magazine, Vol 37, Issue 4, Fall 2023
Doc ID:  2023036
Year of Publication:  2023
Abstract:  
INTRODUCTION Mangalloy works magically! As shot particles it is austenitic and tough but develops a very hard martensitic skin if cold-worked by peening. When the surface wears away, very very slowly, the skin automatically repairs itself. For peening cabinet components the same applies. Mangalloy, also called “manganese steel” or “Hadfield steel”, is an alloy steel containing an average of around 13% manganese. Invented in the nineteenth century it found many applications such as railway line intersections. This article includes elements of the alloy’s history, properties, martensite formation and applications. HISTORY Mangalloy was invented by Sir Robert Hadfield in 1882. It was the first commercially successful alloy steel and had properties different from those of plain carbon steels. Hadfield had been searching for a steel composition that would have both hardness and toughness which plain carbon steels did not have. In the nineteenth century, steelmaking was more of an art than a science. Hadfield became interested in the addition of manganese and silicon to carbon steel. This was because ferromanganese had become available being made cheaply from manganese ores.