Manganese steel casting involves creating intricate metal components using an alloy that contains a high proportion of manganese. This alloy’s exceptional toughness, hardness, and work-hardening properties make it ideal for producing wear-resistant parts like crusher jaws, railroad components, and construction machinery. The casting process allows for the precise formation of complex shapes while maintaining the steel’s durability and abrasion resistance.
Sir Robert Hadfield’s High Manganese Steel contains essentially 1.2% Carbon and 12.5% Manganese and attains it unique characteristic properties only after correct heat treatment. These were the basic principles after years of development that were first published in 1887. Where several varieties of the alloy have been developed, most of the produced tonnage is close to Hadfield’s original composition.
Manganese steel is a low strength but tough and ductile cast steel. Its predominant feature is the ability to work harden from an initial hardness of 240BHN to well over 500 BHN. As the material increases in hardness, the abrasion resistance as well increases. Compared to carbon steel castings, this derived capability proves worthy of some of the most demanding product applications.
Manganese Casting Parts/Classifications
Used most commonly in the mining industry, you’ll find manganese steel in rock crushers, crawler treads, dredge and shovel buckets, and mill liners. Hammers and grates for metal recycling and other high-impact environments such as inside a shot peening machine, all utilize austenitic manganese steel. When used in crushing applications (mining, recycling, etc.), it is the only material that will withstand the harsh, abusive environments. Other applications include window bars in prisons, safes, and bullet-proof cabinets.
Manganese steel castings are also commonly used in the rail industry for switches and crossings. Railway switches on the tracks are under tremendous impact and, when a train wheel hits the surface of the rail, the manganese rail is slightly deformed. This impact and deformation will cause the surface to harden, and the toughened surface will resist future wear.
Properties of Manganese Castings
Many variations of the original austenitic manganese steel have been explored, but only a few have been accepted as industry standard. These typically involve variations of carbon and manganese, with additional allying elements such as chromium, nickel, molybdenum, and others. Of the 10 adopted grades in ASTM A128, below are the 3 most common grades produced at Sivyer Steel Castings.
|CVN (ft-lb) Room Temp
After proper Heat Treatment, initial casting hardness can range from 180-240 BHN. Once the castings are put into service and under load or impact, the work hardened surface will increase in hardness to a maximum of 550 BHN. If cracking of the work hardened layer occur, the crack would rapidly be contained by the tougher, unworked hardened core. The most demanding applications, such as primary rock crushers, have proven manganese steels as the best and economical solution for these situations where downtime cannot be tolerated.
Foundry Casting Process
Producing Manganese steel castings simultaneously with carbon steel castings takes a unique approach, along with excellent process control. Some foundries might separate the two alloy material types completely, but Sivyer Steel Castings uses the similar molding processes and equipment for both. The two alloy steel casting types require different molding methods, including facing sands, riser types, refractory coatings, gating size, shakeout time, and many more. These casting specific instructions are clearly defined and available to each employee through our Odyssey ERP system.
Manganese Steel castings can be made by any of the conventional steel-making methods, however the Electric Arc Melting Furnace process is the most common. Basic melting practices are required because of the severe attack on acid refractories. Sivyer Steel Castings uses (3) 10-ton electric arc furnaces (basic lined) for all of its melting operations, with one furnace solely dedicated to the production of manganese steel.
Over the many years of Manganese Steel Casting production, we have custom tailored the melting process to ensure high quality castings are produced. The melting process, compared to low carbon steels, is different in many aspects, including charge mix, scrap additions, refining and alloy timing, pour rate and temperature, and many more. Our experienced melting crew handles these tasks without fail and only ensure the highest quality steel is poured into each and every mold! Read more on our melting process.
Cleaning & Heat Treatment
After the metal is poured, it’s time to remove the molding sand once the molten metal has solidified. Because of the chemical composition, the gating and risers are knocked off to remove them before heat treating. The proper heat treatment toughens austenitic manganese steel, resulting in safe use across many applications. The standard treatment that produces tensile strength and its normal properties is called solution annealing and quenching, with temps between 1050℃ and 1100℃, and followed by an aggressive water quench in cold water.
Sivyer Steel offers a wide range of finish applications for both manganese and carbon steel castings, including the following:
- Rough and Finish Cleaning
- Weld Upgrade
- Dimensional Gauge Grinding
- Shot Blasting
After many years after its introduction, manganese steel was considered unmachinable, and most all finishing was done by grinding. With machine tool development after the turn of the century, considerable machining is now performed, with tolerances held to thousandths of an inch. Certain essential aspects must be employed for proper machining including robust machine construction, strong work holding, high HP machines, sharp tools, and proper speeds and feeds. Almost all manganese castings Sivyer Steel produces are finish machined, in house, to precise dimensions and surface finishes, both in milling and turning applications. Read more about machining steel castings.
Manganese steel castings can have a variety of inspection requirements. Because the material is non magnetic, standard surface inspections, such as magnetic particle inspection cannot be used. Rest assured, our experienced Quality team will work with you on developing the necessary inspections to guarantee you get a casting that will meet the toughest demands.
Manganese Steel Casting Foundry
Wear-resistant, high integrity castings cannot be made without detailed engineering, excellent molding and melting, robust heat treatment and finishing, and precise machining. We are not a high production foundry but a quality, experienced foundry that cares about our customers. You and your experience are our number one priority. For us, that means continued growth and improvement.
To achieve efficient production of your manganese steel castings, we’ve developed a system of rigging for gates and risers that ensures meticulous planning and high quality. We can handle a full range of castings from one-off parts to high production and everything in between. In house processing of every step, from design to paint, insures we control all steps of the process and offer the lowest cost possible.
Our steel foundry is ISO 9001:2015 certified which is a rigorous but worthwhile process. It means that we’ve developed and established our own Quality Management System (QMS) which reports on internal processes, procedures, and standards. This allows for shorter lead teams and parts that are both consistent and high quality.
Our castings are proudly “Made in the U.S.A.”!