<span style="vertical-align: inherit;">A recent OpenText survey found that 92% of manufacturers believe that corporate social responsibility (CSR) is important to their reputation in the marketplace. Although steel turning is by its nature a manufacturing process that generates a lot of waste, manufacturers can still improve their sustainability without compromising machining safety – even when faced with the unprecedented challenges of the corona pandemic. Here, Rolf Olofsson, Product Manager at Sandvik Coromant, the global leader in cutting processing, explains a different way of looking at steel turning.</span>

<span style="vertical-align: inherit;">According to the 17 global goals for sustainable development that the UN has set, manufacturers are expected to minimize their environmental impact, and then not just be content with optimizing energy consumption. Although CSR is important to companies, Sandvik Coromant estimates that manufacturers waste between 10% and 30% of material in the machining processes, with a typical machining efficiency of less than 50%, which includes design, planning and machining.</span>

<span style="vertical-align: inherit;">So, what can manufacturers do? The UN goals recommend two main ways that also take into account factors such as an increasing population, finite resources and the linear economy. The first is to address the challenges of technology. Industry 4.0 concepts – such as cyber-physical systems, big data or the Internet of Things (IoT) – are often cited as the way forward for manufacturers looking to reduce their waste.</span>

<span style="vertical-align: inherit;">This does not take into account the fact that most manufacturers do not yet use modern machines with digital capabilities in steel turning.</span>

<span style="vertical-align: inherit;">Most manufacturers are aware of the importance of insert selection in making steel turning even more efficient and productive, and how this affects overall function and tool life. But many miss something important by not taking into account the entire tool concept, everything from advanced inserts and tool holders to user-friendly digital solutions. All these factors can make steel turning more sustainable by lowering energy consumption and minimizing waste.</span>

<span style="vertical-align: inherit;">Reduced cutting speeds </span>
<span style="vertical-align: inherit;">Manufacturers face a number of challenges when turning steel. Among other things, getting more details per edge from one and the same insert, increasing the chip removal rate, shortening cycle times, optimizing stock levels and, of course, minimizing material waste.</span>

<span style="vertical-align: inherit;">But what if there is a way to overcome all these challenges that also leads to better overall sustainability? One way to reduce energy consumption is to lower the cutting speed. Manufacturers can maintain productivity by correspondingly increasing the feed rate and depth of cut. In addition to saving energy, it also leads to longer tool life. In steel turning, Sandvik Coromant has seen that an average increase in tool life of 25%, combined with reliable and predictable performance, can minimize the amount of material waste from both the workpiece and the insert.</span>

<span style="vertical-align: inherit;">The right choice of cutting type takes us a bit on the way to the goal. Therefore, Sandvik Coromant is expanding the range with a couple of new carbide grades for P-turning, GC4415 and GC4425. GC4425 provides even better wear resistance, heat resistance and toughness, while grade GC4415 is designed to complement GC4425 when even better performance and heat resistance is required.</span>

<span style="vertical-align: inherit;">Both grades can be used in tough materials such as Inconel, unalloyed steel, stainless steel and ISO-P materials which are particularly complicated and difficult to machine. The right kind can help you process more details in mass production processes and/or batch production processes.</span>

<span style="vertical-align: inherit;">The grade GC4425 provides extremely high processing reliability thanks to keeping the edge line intact. Because the insert can produce more details per edge, less carbide is used to machine the same number of components. Additionally, inserts with consistent and predictable performance help avoid workpiece damage, minimizing material and workpiece scrap. Both advantages reduce the amount of scrap produced. </span>
<span style="vertical-align: inherit;">Both the GC4425 and GC4415 also feature cutting substrates and coatings that have been developed to better withstand high temperatures. This reduces the effect caused by excessive temperatures and in turn allows the insert to maintain the cutting edge line to a greater degree at higher temperatures.</span>

<span style="vertical-align: inherit;">But manufacturers should also consider using cutting fluid with the insert. If you are using a tool with top cooling and bottom cooling, it may be beneficial to turn off the top cooling for some operations. Chip removal, cooling and lubrication between the tool and the material in the workpiece are the primary functions of the cutting fluid.</span>

<span style="vertical-align: inherit;">Correctly applied cutting fluid provides maximum productivity, higher machining reliability and improved tool performance and component quality. Using tool holders with internal coolant supply can also improve tool life.</span>

<span style="vertical-align: inherit;">Layer Scale </span>
<span style="vertical-align: inherit;">Both the GC4425 and GC4415 feature second-generation Inveio® layers, a textured chemical vapor deposition (CVD) aluminum oxide coating (Al2O3) developed for machining. If you look at Inveio under a microscope, you can see that the crystals on the surface are facing the same direction. The crystal orientation has also been significantly improved in the second generation Inveio coating. Now all the crystals in the aluminum oxide coating face the same direction to an even greater degree, creating a strong barrier against the cutting zone.</span>

<span style="vertical-align: inherit;">Inveio gives the insert high wear resistance and longer service life. Tools that last longer are of course good when you want to lower the cost per detail. In addition, the material's carbide substrate contains a high percentage of recycled carbide material, making it one of the most environmentally friendly varieties.</span>

<span style="vertical-align: inherit;">To test the promised properties, the grade GC4425 has undergone pre-market tests with Sandvik Coromant's customers. At a company in the general engineering industry, both a competitor's insert and the GC4425 insert were used in the manufacture of press rolls. An ISO-P grade was subjected to continuous external axial machining and medium rough finishing at a cutting speed (vc) of 200 m/min, feed rate of 0.4 mm/rev (fn) and a depth (ap) of 4 mm.</span>

<span style="vertical-align: inherit;">Manufacturers normally measure tool life in number of machined workpieces (parts). While the competitor's variety machined 12 parts before becoming too worn due to plastic deformation, Sandvik Coromant's insert produced 18 parts, which meant it worked 50% longer with stable and predictable wear.</span>

<span style="vertical-align: inherit;">The example shows the profit that can be made when the right machining elements are allowed to work together, and how recommendations on the first choice of tool and cutting data, from a reliable partner like Sandvik Coromant, can increase machining reliability and reduce time wasted when looking for the right tool. Online tools have also proven popular when manufacturers need to assess which turning inserts and grades best suit their needs, such as the CoroPlus® Tool Guide.</span>

<span style="vertical-align: inherit;">To facilitate the process monitoring itself, Sandvik Coromant has also developed the CoroPlus® Process Control software, which can monitor the processing in real time and act according to programmed protocols if specific problems arise – for example by stopping the machine or replacing a worn cutting tool.</span>

<span style="vertical-align: inherit;">A perfect circle </span>
<span style="vertical-align: inherit;">This leads us to the UN's second recommendation for more sustainable tools: by moving to a circular economy, one can begin to consider waste products as raw materials and return them to a resource-neutral cycle. It is becoming increasingly clear that a circular economy can be both healthy from an environmental perspective and profitable for manufacturers.</span>

<span style="vertical-align: inherit;">This includes the recycling of solid carbide tools – we all benefit by keeping worn tools out of landfills and scrap yards. Both GC4415 and GC4425 contain a large amount of recycled carbide. Making new tools from recycled solid carbide requires 70% less energy than making them from new raw materials, and it also means a 40% reduction in carbon dioxide emissions.</span>

<span style="vertical-align: inherit;">Then we also have Sandvik Coromant's carbide recycling program, which is available to all our customers worldwide. The company buys back worn inserts and solid carbide tools from its customers, regardless of make. It's actually necessary, if you consider how rare and limited the raw materials will be in the long run. The estimated total reserve of tungsten in the world, for example, is about seven million tons, which corresponds to about 100 years of consumption. Sandvik Coromant has now achieved an 80% recycling rate through its carbide tool buyback program.</span>

<span style="vertical-align: inherit;">Despite the current uncertainty in the market, manufacturers cannot forget their other commitments, including CSR. Manufacturers who have a new way of looking at tools and have the right carbide inserts in place can improve their durability without compromising machining safety – and face the challenges that the corona pandemic has created in the market more effectively.</span>