By Theo Simon, Technical Specialist at diversified technology company, 3M
In the oil and gas sector, welded fabrications must resist very harsh operating environments where they may be subjected to high temperatures, pressures and corrosion. Therefore stainless steels such as 6 Moly and Duplex which have a high corrosion resistance – particularly to stress corrosion cracking - are becoming more common across the industry. However, these high performance materials can prove more difficult to work with, especially in terms of grinding.
Precision Shaped Grain (PSG) is an innovative grinding technology, developed by 3M, that cuts faster and lasts longer. Tests have shown that the grinding wheels achieve significantly increased output when compared with conventional products, and abrasives such as Cubitron II Depressed Center Grinding Wheels from 3M can have a major positive impact on the essential metalwork required for oil and gas applications.
The chart below is the result from an extended trial at a customer working in the oil and gas sector making specialist fabrications for offshore applications using high strength stainless steels.
The customer had tried many different abrasive suppliers in the past and selected what worked well for them. 3M collaborated closely with the customer during an extended trial of Cubitron II Depressed Centre Grinding Wheel T27 115mm and 230mm (4.5” and 9”) and the data showed Cubitron II Grinding Wheel outperformed the competitor by 3.3 times in consumable life. It was also grinding 1.4 times faster, under exactly the same conditions. It is clear to see the advantages that the increased life of the consumable will give but what about the speed, what advantage does that bring?
Hand Arm Vibration Syndrome (HAVS) is caused by vibration exposure to the body and research has shown that up to two million industry employees are at a potentially dangerous level of risk. At 3M we develop abrasive consumables to combat this risk. A faster grinding time directly reduces the time on the tool, also known as trigger time. Grinding 1.4 times faster results in 40 per cent less exposure to vibration. This gives the advantage that the operator will be able to work for longer without additional vibration exposure, or work for the same time but with less exposure making the operating environment safer.
Cutting edge technology
The irregularity of conventional ceramic grain (image right) results in it ‘ploughing’ through metal, causing a build-up of heat and resulting in a slower cutting rate; this directly affects product durability, potentially resulting in shorter life. In contrast, precision shaped grain technology (image left) features precisely-shaped, uniformly-sized and vertically-oriented triangles of ceramic abrasive. These self-sharpening structures fracture as they wear, forming new, super-sharp points and edges, which slice cleanly through metal, rather than gouging or ‘ploughing’, allowing the grinding wheel to stay cool and last longer. This has the potential to deliver significant advantages in productivity and consistency, as well as longer service life.