The Science of Forming


 

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We've Come a Long Way, Baby--30 Years of Metals

By: Daniel J. Schaeffler, Ph.D.

Danny Schaeffler, with 30 years of materials and applications experience, is co-founder of 4M Partners, LLC and founder and president of Engineering Quality Solutions (EQS). EQS provides product-applications assistance to materials and manufacturing companies; 4M teaches fundamentals and practical details of material properties, forming technologies, processes and troubleshooting needed to form high-quality components. Schaeffler, who also spent 10 years at LTV Steel Co., received his Bachelor of Science degree in Materials Science and Engineering from the Johns Hopkins University in Baltimore, MD, and Master of Science and Doctor of Philosophy degrees in Materials Engineering from Drexel University in Philadelphia, PA. Danny Schaeffler Tel. 248/66-STEEL E-mail ds@eqsgroup.com: or Danny@learning4m.com

Thursday, November 1, 2018
 

Bethlehem Steel, U.S. Steel, Alcoa, American Can, General Electric, General Motors, Goodyear and Navistar. These eight manufacturing companies were among the 30 listed companies on the Dow Jones Industrial Average in 1988, MetalForming magazine’s first year. None of these currently occupy the Dow, and two no longer exist. A lot can change in 30 years, but much, too, stays the same.

Import relief was an important topic then as it is now. In 1984, the United Steelworkers of America and Bethlehem Steel petitioned the United States International Trade Commission for relief from imports under Section 201 of the Trade Act of 1974. Rather than traversing that path, the government instead successfully negotiated “Voluntary Restraint Arrangements” with many countries in order to limit imports. These lasted until the following decade.

In 1988, hot-rolled steel coil sold for $400/ton. Almost 15 years later, the price bottomed out at $200/ton. Today, it hovers near $900/ton, owing at least partially to industry consolidation and recently imposed tariffs.

Aluminum also has experienced price swings, though the $2000/ton base cost matches 1988 numbers. An influx of Soviet exports 30 years ago and high power prices today contribute to the price fluctuations experienced over these years.

The 10 largest steel companies combined to contribute less than 20 percent of the 780-million-ton global output in 1988. Companies in the USSR produced 21 percent, and combined with companies in Japan (14 percent), the United States (12 percent) and China (8 percent), made up more than half of the world’s total. Today, the market share of the 10 largest steel companies totals 38 percent, with more than 1.6 billion tons produced worldwide. Of this, half is made in China, with the United States, at 80 million tons, placing fourth and representing five percent of the global total. In 1988, U.S. Steel was the fifth-largest steelmaker in the world, producing 14 million tons that year. U.S. Steel still makes the same amount, yet only ranks 26th.

The United States produced 4 million tons of primary aluminum in 1988, representing 20 percent of the world’s total. Those numbers have shrunk to 800,000 tons, representing two percent of the 63-million-ton global total. The 10 largest primary aluminum companies represent 53 percent of market share, with Chinese companies responsible for more than half of the global output. Alcoa, the only U.S.-based company in the top 10, produces 2.3 million metric tons, the bulk of which comes from outside of the United States.

U.S. secondary aluminum production has increased dramatically, owing to scrap-collection programs and significantly lower production-energy requirements, rising from 2.4 million tons in 1988 to 3.7 million tons today, which represents 36 percent of the global total. Chinese companies account for 2 million tons, or 20 percent of the worldwide amount. Production should increase in the coming years as more recoverable scrap becomes available.

Beverage-can production in the United States has increased 25 percent over the past 30 years, from 80 million cans annually to 100 million. A typical beverage can weighed 16.6 g. when MetalForming magazine debuted. The weight has dropped to 14.9 g./can due to manufacturing and processing improvements that allowed for the production of thinner but stronger sections. This may not seem like much, but it translates to five additional cans per pound of purchased aluminum, corresponding to a 15-percent increase in product from each coil.

Globally in 1988, 780,000 people had jobs in the steel industry. Employment has fallen by half in the United States, dropping from 280,000 jobs responsible for producing 90 million tons to 140,000 making 80 million tons. This trend likely will continue—a new Austrian mill can produce 500,000 tons with only 14 people. Aluminum sheet/plate/extrusion mills employ 65,000 people domestically, which should increase as new capacity comes online.

New Alloys

Steel producers were investing in new technologies as MetalForming launched. Continuous casting (concasting) of steel is taken for granted now, but in 1988, 40 percent of U.S. steel production involved ingot casting. The year 1988 saw construction of the first thin-slab continuous caster for flat-rolled steel at a minimill, starting the competition between scrap-based producers and integrated steel companies that had dominated the industry for decades.

Concast steel, with its lower production costs and improved internal quality and more consistent properties, took over from ingot casting. In Japan, the free-world’s leading producer at the time, nearly all steel was continuously cast, a fact at least partially responsible for the belief that Japan produced better steel than the United States. The domestic steel industry was undergoing significant restructuring at the time, closing many plants and laying off hundreds of thousands of workers. Nearly every U.S.-based steelmaker took on equity investments and/or entered into joint ventures with Japanese steelmakers, allowing for both a cash influx and technology transfer. The Japanese steelmakers avoided limits on exports and gained a foothold in the United States at a time when transplant automakers were growing and wanted to buy the same steels as available in their home country.

Hot-mill modifications introduced in the 1980s allowed for controlled-cooling thermal profiles that led to new higher-strength hot-rolled products with enhanced formability. Vacuum degassing units were installed at many steelmakers, enabling the production of steels with greater formability, which were demanded by the automotive industry. This, combined with the ability to roll thinner and wider, a characteristic associated with continuous casting, gave users a greater selection of products from which to choose.

The late 1980s saw the first use of aluminum alloys in exposed automotive applications, with AA6111 and AA6016 recently commercialized. Development continued, leading to the creation of AA6016A and AA6022 in 1995, and AA6451 a decade later. These represent the workhorse grades for high-quality stamped sheets in use today.

Panels and Press Shops

Although noncontact quality-control tools are in routine use in many press shops today, the 1980s offered fewer options. Computing power, an expensive proposition back then, required extensive floor space. And what was programmed into computers? Machine control software was understood only by a select few.

Any tool considered relatively fast and easy to use was looked upon as providing indispensable information. The Limiting-Dome-Height (LDH) LDH test was used in stamping plants 30 years ago to determine if a split part resulted from sheetmetal properties or from the stamping process. Unfortunately, only upon a lengthy evaluation occurring after the purchase of a lot of test equipment was it determined that too many variables existed to consistently draw the same conclusion under supposedly identical test conditions. The LDH test is better suited for lubricant evaluations, where it continues to be used today.

Forming simulation, so critical now in saving significant time and money during part development, was essentially nonexistent in 1988. Established yield criteria could not accurately comprehend anisotropic forming behavior. Nonlinear finite-element analysis was possible, but excessive computing time on workstations limited its routine use. Thirty years later, you can run simulations on your PC. Simulation-as-a-service business models exist today, allowing you to upload CAD files and receive results a short time later. Current programs accurately predict thinning, stresses and strains, and metal flow for many different sheetmetals and forming processes. MF

 

See also: 4M Partners, LLC, Engineering Quality Solutions, Inc.

Related Enterprise Zones: Materials/Coatings


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