Expanding and Flexing Heating Processes

As noted by the Steel Market Development Institute, steel manufacturing processes represent a significant portion of the value imparted to engineered automotive parts, creating the basis from which processes like forging can complete the value proposition. One of the top suppliers of forging raw materials is TimkenSteel, which produces up to 2 million tons/year of carbon steel, alloy, and micro-alloyed steel for automotive, oil-and-gas, and general industrial applications. Since it was launched in 2013 the Ohio steelmaker has been investing in its production capabilities, continue to build the means for manufacturing high-quality products that will ensure the value of the components produced in the next phase of the supply chain.

Late in 2017 TimkenSteel completed the product testing phase for its Advanced Quench-and-Temper Facility at the Gambrinus Steel plant in Canton, OH — a project first announced in 2015 as a $40-million investment for induction preheating and heating furnaces, to austenitize and temper 4- to 13-in. bars and tubes at a rate of 50,000 tons/year.

The AQTF was designed and built by SMS group, which gained the Final Acceptance Certificate for the project from TimkenSteel last November.

SMS designed the compact installation to impart specific levels of mechanical strength to various steel grades and products. The line includes a combination of induction preheaters and combustion furnaces – which impart the austenitizing and tempering effects to the various steel grades. The walking-beam furnaces heat the bars or tubes to a uniform temperature, usually over 1,500°F, followed by quenching in a hot liquid (usually oil or water), or air, depending on the grade.

Subsequent product cooling takes place in a newly developed “quenching shell,” an advanced OD/ID water sprayer, characterized by high-quench severity and, at the same time, flexibility for adapting the process according to product requirements.

The new line is able to treat 10 tons per hour of bars and heavy-walled tubes, up to 13 inches in diameter, in strict compliance with specified values, according to SMS.

“We found that SMS was able to bring the best technology to meet our needs and satisfy our customer demand. The commissioning effort went very well,” according to Carolee Vanicek, director of tube manufacturing there.

During the line commissioning last year, a wide array of intensive tests was carried out. This included certification of the combustion heating furnaces in line with the SAE ASM2750-E standard, which calls for extremely demanding temperature homogeneity (± 3°C for furnaces of Class 1), as a requirement for producing aerospace-quality material.

According to the new line’s developer, a range of seamless mechanical tubes and SBQ (Special Bar Quality) products have been processed by the AQTF, from 6 to 12 in (beyond the specified range of 4 to 13 in.) These include a wide variety of different steel grades, reflecting TimkenSteel’s portfolio. The tests were performed with increasing rates of hourly throughput, to "stress test" all the line components.

The AQTF start-up was a something of a finale for TimkenSteel’s centennial celebration during 2017, and followed a series of capital investments it has made in recent years to expand and improve its production capabilities: the 3,300-ton inline forging process in 2012; an intermediate finishing line for seamless tubes in 2013; and a jumbo vertical bloom caster in 2014.

“Everyone has risen to the challenge for improving safety, quality and efficiency,” Vanicek said of the latest Gambrinus plant expansion and process improvement. “The areas work together to benchmark one another and develop strong solutions for improvement.”

While the current advances emphasize heat-treating capacity and flexibility, Vanicek foresees the TimkenSteel operations “continuing to serve evolving and challenging markets with the best value-added long products.”