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HP Plate provides this list of frequently asked questions and answers as an informational resource for our web site visitors. If you would like to ask a question that we can add to this page, please click here to ask us. We will post our answer here as well.

Frequently Asked Questions and Answers

• Question: Can I cut or drill a hole in an HP overlay plate?
• Answer: No. The chromium-carbide layer is not drillable or machineable. When necessary, you may be able to cut it with plasma, waterjet, or arc-gouging.

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• Question: Is it normal to see cracking in hardfacing plating?
• Answer: It depends on the hardfacing alloy. Many chromium carbide alloys check-crack when cooled to moderate temperatures; this is normal. Other alloys, such as the austenitic and martensitic, do not crack when applied properly. Check cracking can be seen as cracking perpendicular to the bead length. This occurs by the high stress that is experienced when the weld metal cools. The cracking stops at the parent metal underneath, as long as the parent metal is not brittle. If the parent metal is hard or brittle, you should choose a buffer layer of a softer, and tougher, weld metal.

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• Question: What are the most popular methods for applying hardfacing?
• Answer: The most popular methods include: flux cored arc welding (FCAW), gas metal arc welding (GMAW), shielded metal arc welding (SMAW), submerged arc welding (SAW), gas tungsten arc welding (GTAW), oxyfuel welding (OFW) or oxyacetylene welding, plasma transferred arc welding, laser welding, thermal spray, and brazing. FCAW and GMAW may have similar levels of popularity. However, there is a growing preference to use semi-automatic and automatic welding methods.

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• Question: What metals can be protected with hardfacing?
• Answer: Carbon and low-alloy steels with carbon contents of less than 1 percent can be hardfaced. High-carbon alloys may require a special buffer layer. Some of the base metals that can be hardfaced include: stainless steels, manganese steels, cast irons and steels, nickel-base alloys, copper-base alloys.

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• Question: What is hardfacing?
• Answer: Hardfacing is also known as hardsurfacing. It is the process of adding wear-resistant weld metals to the surface of a metal part to protect it from wear and abrasion. Adding the weld metal plates can be achieved through welding or joining.