Group: FAQs

It depends on the type of wear involved, but in the case of abrasive wear—by far the most predominant wear mechanism—the ASTM Intl. G65 Dry Sand Rubber Wheel Test is used extensively. This essentially is a test in which the sample is weighed before and after the test, and the result usually is expressed in… Continue reading If hardness is unreliable, then how is wear measured?

No, this isn’t a good idea. A martensitic alloy and a chromium carbide alloy can have the same hardness, let’s say 58 HRC, and perform vastly different under the same abrasive conditions. The metallurgical micro-structure is a better measuring stick, but that isn’t always available. The only time hardness can be used to predict wear… Continue reading Can hardness values be used to predict abrasion resistance?

Complex carbides generally are associated with the chromium carbide deposits that have additions of columbium, molybdenum, tungsten, or vanadium. The addition of these elements and carbon form their own carbides and/or combine with the present chromium carbides to increase the alloy’s overall abrasion resistance. They can have all of these elements or just one or… Continue reading What are complex carbides?

Generally, these are iron-base alloys that contain high amounts of chromium (greater than 18 percent) and carbon (greater than 3 percent). These elements form hard carbides (chromium carbides) that resist abrasion. The deposits frequently check-crack about every 1/2 in., which helps relieve stress from welding. Their low friction coefficient also makes them desirable in applications… Continue reading What is chromium carbide hard-facing?

Check-cracking, or checking as it’s sometimes called, occurs in the metal carbide families and can be seen as cracks that are perpendicular to the bead length. They generally occur from 3/8 to 2 inches apart and are the result of high stresses induced by the contraction of weld metal as it cools. The cracks propagate… Continue reading What is check-cracking?

It depends on the hard-facing alloy. Many chromium carbide alloys check-crack when cooled to moderate temperatures; this is normal. Others, such as the austenitic and martensitic families, don’t crack when applied with proper welding procedures.

This includes all hardenable steels with Rockwell hardness from 20 to 65. This group, similar to tool steel, hardens upon cooling. They are good for metal-to-metal and abrasive wear. They also can withstand a great deal of impact. Martensitic. This includes all hardenable steels with Rockwell hardness from 20 to 65. This group, similar to… Continue reading Is there a convenient way to categorize the many alloys when determining which hard facing to use?

Carbon and low-alloy steels with carbon contents of less than 1 percent can be hard-faced. High-carbon alloys may require a special buffer layer. The following base metals can be hard-faced: Stainless steels Manganese steels Cast irons and steels Nickel-base alloys Copper-base alloys

Yes. Many different categories of wear exist—too many to cover in one article—but the most typical modes of wear are as follows (percentages are estimates of total wear): Abrasion—40 percent Impact—25 percent Metallic (metal to metal)—10 percent Heat—5 percent Corrosion—5 percent Other—5 percent Most worn parts don’t fail from a single mode of wear, such… Continue reading Wear is such an all-encompassing term. Can it be broken down into more manageable categories?

Metal parts often fail their intended use not because they fracture, but because they wear, which causes them to lose dimension and functionality. Hard-facing, also known as hard-surfacing, is the application of buildup or wear-resistant weld metals to a part’s surface by means of welding or joining.