A Texas-based steel products manufacturer with EAF capacity that produces a diverse line of high-quality value-added steel products was recently acquired by a global industrial alliance and added to the latter’s resources, energy, transportation, and infrastructure group.
Liberty Steel USA’s acquisition of Keystone Consolidated Industries, Inc. (KCI) from Contran Corporation, creates one of the country’s largest producers of wire rod. Liberty Steel USA is part of the GFG Alliance; a global group of energy, mining, metals, engineering, logistics, and financial services businesses, headquartered in London. Sanjeev Gupta is the Executive Chairman.
GFG North American CIO Grant Quasha
Keystone Steel and Wire, a division of KCI, has a 100+ year history in the steel and steel products business. The deal includes Keystone’s top-producing wire rod facility, which houses a 1.1mt capacity electric arc furnace (EAF), and an MBQ/SBQ bar mill.
Liberty Steel USA will have up to 1.8mtpa of EAF melting capacity, 2mtpa of wire rod rolling capacity, significant value-added downstream businesses and over 1,300 employees. The combined company will have operations in Illinois, Ohio, South Carolina, New Mexico, Texas, and Georgia.
“KCI and its businesses offer Liberty the chance to merge our existing U.S. steel business with one of the country’s most productive wire rod operations,” said GFG North American CIO Grant Quasha. “Combined with Liberty Steel Georgetown, KCI will increase our downstream capabilities, create critical synergies, add strong management and provide better value and products for customers as we advance our U.S. steel business to our 5mt pa goal.”
Main photo caption: GFG North American Chief Investment Officer Grant Quasha and Executive Chairman Sanjeev Gupta
Induction Hardening Tips: Equipment Selection for Scan Hardening, Part 3
This is the third installment of a multi-part column on equipment selection for induction heat treatment. Part 1, Dr. Valery Rudnev On . . . Induction Hardening Tips: Equipment Selection for Scan Hardening, covered types of scanners, scan hardening system setup, quenching challenges, maximizing process flexibility, and computer modeling. In Part 2, Dr. Valery Rudnev discussed another critical aspect of induction scan hardening: inductor design subtleties and a comparison of different fabrication techniques (brazing vs. CNC
machining vs. 3D printing).
In this installation, Dr. Rudnev focuses on Moveable Inductor versus Moveable Part.
Moveable Inductor versus Moveable Part
As stated in one of the previous installments of this column, when a scan processing mode is chosen, either the inductor or the part or both may be moved during the heating and quenching. This installment discusses the applicability of those approaches (movable inductor vs. movable part), as well as pros and cons associated with both techniques.
Figure 1. An example of scan hardening of track shoes for earth-moving machines that often specify deep hardness case depths (up to the 24 mm).
The choice to move the inductor or to move the part is primarily based on required production rate as well as on the size, weight, and geometry of the component compared to the size, weight, and geometry of the inductor: in other words, it depends on which of the two is easier to move.
Weight is an important factor because the movement can occur several hundred times each day and, in some cases of high production, even several thousand times per day. For example, during induction surface hardening of track shoes for earth-moving machines that often specify deep hardness case depths (up to 24 mm), it is much easier to move the inductor around the workpiece instead of moving the track shoes, the weight of which can exceed several thousand pounds. (Figure 1)
When moving the inductor, both flexible cables and hoses are used or the inductor is hard-bused to the transformer and the transformer or heat station moves with the inductor. In some cases, the power supply itself may be moved at a moderate rate to scan a stationary workpiece [1]. Another example of moving the inductor is surface hardening of trailer axles. (Figure 2)
Figure 2. (Left image) Horizontal scanner to induction harden both ends of a trailer axle. A walking beam system was incorporated into the machine for part transfer. At the heating station, the axle is lifted off the beam and the power supply and inductor are indexed to position for scan hardening. After the completion of surface hardening of one end, the axle is then lifted off the transfer mechanism and rotated 180° to induction harden the opposite end. Heavy-duty precision shafting and bearings are used for stability and consistency. (Right image) shows a close-up of a movable inductor to scan harden trailer axle ends. Heating time is less than 8 s per axle end.
The length of the part to be heated is also an important consideration When a component is of moderate weight, it is obviously preferable to move the part rather than the inductor. For example, it is much easier and more cost-effective to design a hardening system that anticipates moving a workpiece that weighs less than 0.25 kg (<0.5 lb) rather than moving an entire power supply, as it is shown in Figure 3.
Figure 3. Horizontal scanner that provides a maximum scan rate up to 200 mm/s (8 in./s). (Courtesy of Inductoheat Inc., an Inductotherm Group company.)
In other cases, it may not be practical to move very large and elongated components. It would consume too much floor space to move the part through a stationary inductor. In the case of low production rates, the best choice might be to move the inductor, but the length of the high-frequency power leads could become a problem with respect to voltage drop and power loss. In this case, it is preferable to move the inductor with the power supply attached. Then, the moving cables are operating at a low frequency (50–60 Hz) with lower voltage drop and power loss. In the case of high production, continuous horizontal systems may be more suitable.
The consideration of the length of the leads (e.g., cables or buses) from the power source to the inductor is important. They should be as short as possible to conserve energy and to allow the power source to operate properly without reaching any limits (for example, voltage limit). If these leads are too long, the inductance increase can be so significant that it may result in a substantial power loss and voltage drop. The voltage drop in the leads may even exceed the voltage at inductor’s terminals. Long leads could net an excessive total needed power, a measurable reduction in energy efficiency, and potential concerns regarding the process repeatability owing to the possibility of an appreciable inductance change of the flexible leads during their motion, that in some cases may negatively impact process repeatability.
Whether moving the inductor or moving the part, the induction system can be designed to be efficient and robust in order to ensure smooth and consistent operation and the production of quality parts.
I recommend Reference #1 to readers interested in further reading on this subject.
References
V. Rudnev, D. Loveless, R. Cook, Handbook of Induction Heating, 2nd Edition, CRC Press, 2017.
Dr. Valery Rudnev, FASM, IFHTSE Fellow, is the Director of Science & Technology, Inductoheat Inc., and a co-author of Handbook of Induction Heating (2nd ed.), along with Don Loveless and Raymond L. Cook. The Handbook of Induction Heating, 2nd ed., is published by CRC Press. For more information click here.
A thermal processing equipment manufacturer based in Maumee, Ohio, recently supplied a batch integral quench furnace for a metal treating company in Raleigh, North Carolina, that services the automotive, aerospace and defense sectors, as well as general manufacturing.
East Carolina Metal Treating’s (ECMT) purchase of the Allcase® Batch Integral Quench Furnace from Surface® Combustion Inc. is a repeat order. Identical to the previously commissioned Allcase furnace, the new equipment is configured to process 36” wide by 48” long by 36” high workloads that weigh up to 4,000 lbs. In addition, Surface has supplied two air cool stations, a scissors lift table, and two stationary load tables that integrate with an existing IQ line.
The new Allcase works seamlessly with ECMT’s existing charge car, tempers, and washer, following the incorporation of a purchaser specified controls system to match the existing UPC controls on the initial order, and features a Vertical Radiant Tube Heating System with direct spark ignition and flame monitoring, recuperated burners and plunge cooling. A maintenance platform with access stairs allows for fast and easy maintenance. An integrated Top Cool Chamber was provided to further expand process applications, a hallmark of the Allcase furnace which was invented for the greatest range of thermal processing; all case-hardening and non-case hardening applications under controlled atmospheres.
“As always our team did a great job but a special shout out to the Surface Combustion and UPC Teams involved in this project. This was our first project with Surface and their reputation holds true as expected,” said Jamie Ramm, president of ECMT.
Heat TreatToday Technical Tuesday contributor, Dr. Valery Rudnev, FASM, IFHTSE Fellow, “Professor Induction”, and Director of Science and Technology at Inductoheat, Inc, is the featured speaker of an ASM International Materials Solutions webinar titled “Simple Solutions for Common Induction Heating Challenges: Lessons Learned”.
Dr. Rudnev will present this webinar on Thursday, January 24, 2019, 2 pm, and address:
Induction hardening of powertrain transmission and engine components
Failure analysis
How to avoid cracking in induction hardening
Subtleties of heating parts with holes, fillets, and other geometrical irregularities
Re-hardening (re-austenitization) of previously hardened parts
Novel inverters that allow instant and independent adjustment of both frequency and power
Selected challenges when applying induction tempering
Reducing process sensitivity and improving robustness and flexibility of induction systems.
Note: Attendees will earn a professional development hour for attending the webinar.
This webinar is sponsored by Inductoheat, Inc. For more information and to register, click here.
A North American steel and steel products manufacturer recently announced plans to build a state-of-the-art plate mill with heat treating included in its range of processing.
Leon Topalian, Nucor’s Executive Vice President of Beam and Plate products
Nucor Corporation, based in Charlotte, North Carolina, will invest $1.35 billion to build the mill, which will be based in the U.S. Midwest and produce cut-to-length, coiled, heat-treated, and discrete plate ranging from 60 to 160 inches wide, and in gauges from 3/16 of an inch to 14 inches in thickness, enabling Nucor to supply plate products that the Company does not currently offer.
“By building this state-of-the-art plate mill in the Midwest – the largest plate-consuming area in the United States – we will enhance our ability to serve our customers in the region while also furthering our goal of meeting all the steel needs of our customers around the country,” said Leon Topalian, Nucor’s Executive Vice President of Beam and Plate products. “We expect to select a site for the new mill early this year. Our team is poised and ready to take the next step in advancing our position in steel plate products.”
Nucor’s Board of Directors has approved an investment of $1.35 billion to build the mill, which is expected to be fully operational in 2022 and will be capable of producing 1.2 million tons per year of steel plate products.
John Ferriola, Chairman, CEO & President of Nucor
“This investment is consistent with our drive to continue delivering sustainable, profitable growth and superior returns for shareholders,” said John Ferriola, Chairman, CEO & President of Nucor. “Together with the significant share repurchases completed in 2018, the Board’s decision to fund this high-return opportunity demonstrates our commitment to balanced capital allocation. We have a strong foundation to build upon as we advance our goal of leading in every market in which we compete.”
Nucor currently operates plate mills in North Carolina, Alabama, and Texas.
Two major international steel corporations recently announced plans to invest in existing steel mills in along the northwest Indiana lakeshore, as part of collective bargaining agreements reached with the United Steelworkers union.
ArcelorMittal, based in Luxembourg, and Pittsburgh-based U.S. Steel together will invest $5.6 billion into their U.S. operations in an effort to ensure that the local mills remain sustainable, including Gary Works, U.S. Steel’s largest mill.
During the day-to-day operation of heat treat departments, many habits are formed and procedures followed that sometimes are done simply because that’s the way they’ve always been done. One of the great benefits of having a community of heat treaters is to challenge those habits and look at new ways of doing things. Heat TreatToday‘s 101 Heat TreatTips, tips and tricks that come from some of the industry’s foremost experts, were initially published in the FNA 2018 Special Print Edition, as a way to make the benefits of that community available to as many people as possible. This special edition is available in a digital format here.
In today’s Technical Tuesday, we continue an intermittent series of posts drawn from the 101 tips. The category for this post is Quenching, and today’s tips–#8, #38, and #81–are from three different sources: Dan Herring, “The Heat Treat Doctor®”, of The Herring Group; Combustion Innovations; and Super Systems, Inc.
Heat TreatTip #8
14 Quench Oil Selection Tips
Dan Herring, “The Heat Treat Doctor®”, of The Herring Group
Here are a few of the important factors to consider when selecting a quench oil.
Part Material – chemistry & hardenability
Part loading – fixturing, girds, baskets, part spacing, etc.
Part geometry and mass – thin parts, thick parts, large changes in section size
Distortion characteristics of the part (as a function of loading)
Stress state from prior (manufacturing) operations
Oil type – characteristics, cooling curve data
Oil speed – fast, medium, slow, or marquench
Oil temperature and maximum rate of rise
Agitation – agitators (fixed or variable speed) or pumps
Effective quench tank volume
Quench tank design factors, including number of agitators or pumps, location of agitators, size of agitators, propellor size (diameter, clearance in draft tube), internal tank baffling (draft tubes, directional flow vanes, etc.), flow direction, quench elevator design (flow restrictions), volume of oil, type of agitator (fixed v. 2 speed v. variable speed), maximum (design) temperature rise, and heat exchanger type, size, heat removal rate in BTU/hr & instantaneous BTU/minute.
Keep water out of your oil quench. A few pounds of water at the bottom of an IQ quench tank can cause a major fire. Be hyper-vigilant that no one attempts to recycle fluids that collect on the charge car.
According to Super Systems, Inc., there are one of three problems to consider if your quench is just not cutting it. Although SSI focuses more on atmosphere control systems, when parts come out soft, the problem isn’t always the atmosphere – sometimes it’s the quench. Here are three things to consider regarding your quench:
First, check the composition of the quench media. Is it up to spec? Does it need to be refreshed?
Is the quench receiving adequate agitation to thoroughly quench the load?
Is the quench at the right temperature? If the bath is too warm when the load enters, quenching won’t go well!
Photo credit: Heat Treat Today FNA 2018; Super Systems, Inc.
If you have any questions, feel free to contact the expert who submitted the Tip or contact Heat TreatTodaydirectly. If you have a heat treat tip that you’d like to share, please send to the editor, and we’ll put it in the queue for our next Heat TreatTipsissue.
At 41 feet long and 21 feet wide, weighing in at nearly 10,000 pounds, the world’s first 3D-printed bridge has been approved and tested for pedestrian traffic in Eindhoven, in the Netherlands, approximately 90 minutes south of where it was constructed by four robots in Amsterdam.
MX3D, in partnership with more than 30 global industrial partners, completed the final deck and structural tests and finalized the sensor design earlier this year. In October, at Dutch Design Week, visitors provided the foot traffic needed to generate the first data set from the sensing system. The next phase will be to use the sensor data to build a digital twin model to monitor foot traffic in real-time, then installation over a canal in Amsterdam.
The structure is a testament to the possibilities of large-scale 3D printing, but this is just the tip of the iceberg. ~ ThomasNet.com
Controlling process temperature with accuracy and without extensive operator involvement is a crucial task in the heat treat shop and calls for the use of a temperature controller, which compares the actual temperature to the desired control temperature, also known as the setpoint, and provides an output to a control element. This comparative process relies upon an algorithm, the most commonly used and accepted in the furnace industry being the PID, or Proportional-Integral-Derivative, control.
“This popular controller is used because of its robust performance in a wide range of operating conditions and simplicity of function once understood by the processing operator,” writes Real J. Fradette, a Senior Technical Consultant with Solar Atmospheres, Inc, and the author of “Understanding PID Temperature Control as Applied to Vacuum Furnace Performance” (with William R. Jones, CEO, Solar Atmospheres, Inc, contributing).
The PID algorithm consists of three basic components, Proportional, Integral, and Derivative which are varied to get optimal response. If we were to observe the temperature of the furnace during a heating cycle it would be rare to find the temperature reading to be exactly at set point temperature. The temperature would vary above and below the set point most of the time. What we are concerned about is the rate and amount of variation. This is where PID is applied. ~ Fradette
In this week’s Technical Tuesday, we direct our readers to Fradette’s article at Solar Manufacturing’s website where he and Jones cover the following on PID temperature controllers:
Definitions, e.g., Closed Loop System; Proportional (GAIN); Integral (RESET); and Derivative (RATE)
Actual operation of a PID temperature controller, including understanding PID dimensions and values; and general rules for manually adjusting PID
John Hubbard, chairman of Thermal Process Holdings
Following the acquisition of a Wisconsin heat treat company, finalized last week, an industry holdings group recently announced the purchase of a high-quality heat treat provider focused in tool and die work.
Thermal Process Holdings (TPH) acquired P & L Heat Treating (P&L) of Youngstown, Ohio, in their continuing efforts to build a leading thermal processing company based on value-added services.
“We are delighted to partner with Bill Pociask and the P&L team. P&L is a well-run heat treating operation providing high-quality service. Both Bill Pociask and P&L are excellent additions to the TPH group,” said John Hubbard, chairman of TPH.
Bill Pociask, founder and president of P&L
“I am excited to work with the TPH group of companies. There are many opportunities for us to help each other grow and continue to serve our customers. The future is very bright for P&L,” said Bill Pociask, founder and president of P&L.
TPH also owns and operates: Diamond Heat Treat, based in Rockford, Illinois; Certified Heat Treating, based in Springfield, Ohio; and Hudapack Metal Treating, based in Elkhorn and Franklin, Wisconsin.
TPH was formed by Calvert Street Capital Partners and John Hubbard (former CEO of Bodycote, PLC) to pursue a buy-and-build strategy in the thermal processing industry. You can listen to an interview with John Hubbard regarding the strategy of Calvert Street Capital Partners, conducted by Heat Treat Today‘s publisher, Doug Glenn, at this Heat TreatRadiolink.
