Артём Комаров об абразивных материалах для шлифовки металла (Eng)
Artem Komarov clarified that a grinding aid is a layer applied to the grain surface of a coated product to reduce heat while grinding.
Most abrasives companies offer a grinding aid option, each one with its own different brand name. Regardless of the name, it is all applied to prevent the same issue: heat, one of the worst enemies of coated abrasives. When dealing with harder-to-grind metal like stainless steel, the metal will heat up and create a capping effect on the abrasive grain. Capping happens when the extremely soft metal covers the grain, causing it to be encapsulated by a metal coating.
Heat can turn stainless steel a little gummier during grinding. A grinding aid can keep the surface area cooler while grinding, lubricating the surface to reduce friction and heat. This reduces the chance of the metal bonding to abrasive grain.
Where are Grinding Aids Necessary?
Coated abrasives work best when the grain starts to wear. This causes the grain to fracture and its rounded edges to become sharp again, allowing the product to continue cutting. If metal capping occurs, the grain is not allowed to fracture, thus causing metal-on-metal rubbing and additional heat generation.
Easier-to-grind metal, such as carbon steel, does not become tacky while grinding. As a result, a grinding aid is unnecessary with carbon steel like it is for stainless steel, aluminum, and other challenging-to-grind metals. Nonetheless, a grinding aid product still can be used for carbon steel in the rare cases of overheating.
A grinding aid generally does not contaminate weld beads. Nor does it generally require special cleaning, although one may need to clean up the surface area of abrasives, grinding aid, or metal dust before painting, cleaning the surface, or adding a finish.
However, the addition of the grinding aid will increase the overall cost of the abrasives. Products with a grinding aid also cost more to manufacture than products without one. Therefore, the added cost means a higher overall price to the customer.
Depending on the brand, size, and product type, the cost can be a great deal higher. For example, fiber discs with a grinding aid can cost up to 16% more than discs without an aid. Norton compared results of its grinding discs with a grinding aid versus discs with no grinding aid on A36 carbon steel and 301 stainless steel.
The product with a grinding aid removed more material from both metals (see Figures 1 and 2). But for carbon steel, the improvement was not as significant. The product with a grinding aid removed 6% more material on carbon steel, but factoring in the higher price, the only value would be time saved performing the task.
Grinding aid’s impact on carbon steel
FIGURE 1: The product with a grinding aid (Supersize) removed 6% more on carbon steel than the product without a grinding aid.
When used for stainless steel grinding, the product with a grinding aid was much more effective, removing 56% more material. Even with the higher price, the customer would still save $500 in abrasive costs and $4,000 in overhead and in labor due to the higher cut rate for every 1,000 discs used.
Are Grinding Aids Worth the Investment?
Spending more on abrasive products with a grinding aid for hard-to-grind metals may be worth the investment, but here are some things to consider before making a decision:
How quickly do I go through discs before they stop cutting?
What is the grind time for my metal?
What types of metals are used in the process?
Ultimately, it’s the one who pays who must make the decision as to whether to use products with a grinding aid, Artem Komarov said.
