November 2023 Volume 5

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MATERIALS

The fewer inclusions, the cleaner the steel. The cleaner the steel, the better its performance. Certified air-melt technology achieves cleanness on par with vacuum-arc remelted (VAR) steel. This option provided the customer with improved power density and durability at substantially lower cost. When the OEM trialed the air-melted steel against other products, a trend emerged: lesser-quality steels consistently faltered under rigorous testing conditions. But with certified air-melt SBQ steel, testing results showed increased power capacity, reduced size and weight and improved durability and fatigue life. As demonstrated, forgers who collaborate with their SBQ steel suppliers to develop a deeper comprehension of the influence of clean steel technology have a competitive edge in delivering superior quality to their customers. The Power of Precision

suppliers to ensure the selection of the optimal SBQ steel grades for the toughest bolting requirements. Testing New Limits

SBQ steel is also the foundation on which reliable bearings are built. Within powerful machinery, the repercussions of using subpar materials can be quite severe. Numerous standards exist that evaluate steel cleanness for applications such as bearings using methods like macroetch, fracture testing or magnetic particle testing as well as light optical microscopy. Only one standard incorporates all of these: ASTM® E45, "Standard Test Methods for Determining the Inclusion Content of Steel.”2 A limitation with E45 (and other similar optical methods) is that, as steel cleanness has improved over the years, the methods described in the standard have become less discriminating. Bearing manufacturers have substantiated this through life testing of steels exhibiting comparable E45 values but yielding different fatigue outcomes. ASTM E45 is a valuable tool for broadly categorizing cleanness but falls short in distinguishing exceptionally pure steels. To identify true "bearing quality" steels, additional testing methods, like TimkenSteel’s ability to combine scanning electron microscopy with simultaneous energy-dispersive X-ray spectroscopy (SEM EDS), surpass E45 to create a more comprehensive assessment. In this case, optical imaging allows for examining a larger area with precise chemical analysis of detected inclusions. While E45 identifies acceptable cleanness levels for "bearing quality," additional testing enhances sensitivity for characterizing nonmetallic inclusions and predicting performance. Industry standards tend to be geared toward ensuring efficient and cost effective order fulfillment, often at the expense of sensitivity. For forgers and their bearing customers, the optimal approach is to work with their SBQ suppliers to use a balanced combination of methods to ensure consistent steel quality and optimized downstream processes.

In many applications, a malfunctioning bolt has little consequence and will be swiftly replaced with no repercussions. However, as oil and gas exploration ventures into evermore formidable territory, the magnitude of bolting failures can be catastrophic to deepwater drilling or land-based fracking operations. When every bolt counts, forgers turn to SBQ steelmakers to drive higher standards for safety and quality. Some, like TimkenSteel, actively participate on the technical committee of the American Petroleum Institute® (API). Recognizing the imperative for standardized, high-performing bolting solutions, the committee created the API 20E specification that establishes distinct bolting requirement levels, including for situations where any possibility of failure is unacceptable and could lead to the release of hydrocarbons into the environment. API 20E-compliant fasteners are now essential for many oil and gas bolting applications like valves, surface trees, subsea wellheads and drill-through equipment. The standard mandates the use of alloy and carbon steel bolts that meet strict criteria for mechanical strength and corrosion resistance. In high-stakes environments, clean steel helps to ensure the utmost integrity of the equipment and infrastructure involved. Oil and gas OEMs rely on forging specialists who collaborate with their

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