Above: Meet the press. Michael O’Brien, vice president of production and corporate planning at Hyundai Motor, introduces the company’s product line to journalists and photographers at the 2012 Chicago Auto Show. Making its debut was the Elantra GT (red car), containing 60 percent HSLA and AHSLA steels.

Full-line automaker extends HSLA and AHSLA advantages throughout its product price range

March 2013 - Steels with high-strength low-alloy (HSLA) and advanced high-strength low-alloy (AHSLA) metallurgy are the norm in designing lightweight, fuel-efficient automobiles. Until recently, the cost of these materials skewed their use toward the high end of the market. They were generally out of reach for lower-priced vehicles.

Now comes Hyundai Motor Co., which has raised the bar for other automakers by lowering the price points for cars that incorporate HSLA and AHSLA steels. Its entire product line, ranging from the just-over $15,000 Accent to the mid-$60,000 Equus, incorporates some form of advanced technology steel.

Do it yourself

The secret, say company officials, is having your own steel mill and metallurgical engineering laboratory. Hyundai Steel’s primary integrated operation is in Dangjin, South Korea, 90 minutes southwest of Seoul, and the steel technology center employs more than 400 engineers and metallurgists. A smaller mill produces steel at Inchon, a household name during the Korean War. Hyundai declares that it is the first worldwide automaker to have its own steel plant since Henry Ford built the River Rouge works in Dearborn, Mich., in the 1920s. (Tata of India also produces steel, but it is considered to be a regional car builder.)

The steel mill alliance is a supply chain trump card. Alloys are customized for automotive applications and put into production faster than relying on outside vendors. Collaborating with in-house designers, metallurgists and engineers significantly shortens product lead times and reduces development costs.

Wait; there’s more. Hyundai pays more for HSLA and AHSLA steels, of course, primarily because of the addition of alloys such as manganese. But the downstream advantages more than compensate, with the use of less metal; reduced component count; and faster, less complex assembly.

Breaching the walls

Hyundai began its career as an automaker in 1967, and its Hyundai Steel affiliate joined the larger Hyundai Motor Group in 2001. The old model of the auto industry, in which each department does its job in isolation and heaves its completed work over the wall to the next department, never took hold at Hyundai. Product development was a collaborative process from the beginning.

In Hyundai’s vehicle development system, metallurgists meet more with manufacturing engineers than with designers, says Frank Ahrens, vice president of global corporate communications. “Metallurgists develop the sheet metal formula used to create car body surfaces and typically deal with metal process engineers. However, our advanced design people, while trying to come up with new car designs and new design strategies, will meet with Hyundai Steel engineers to determine what is possible and what may be possible.”

Wonsuk Cho, Ph.D., is the senior executive vice president of Hyundai Steel. He emphasizes the collegial relationship with its automaker partner. “Direction and schedule for developing advanced high-strength low-alloy steel that is required by Hyundai Motor is determined through close consultation of engineers from the two companies,” he says. “This close relationship enables the two companies to develop high-grade steel jointly.

“In addition, Hyundai Motor can take advantage of Hyundai Steel’s specialization in materials. For example, Hyundai Steel can provide precise equipment for material analysis.”

In spite of the teamwork approach to design and development, Hyundai Steel isn’t guaranteed a captive customer. It must compete for Hyundai Motor business like any other supplier. As Cho says, “Hyundai Steel is considered an independent supplier with the same supplier-customer relationship as any other vendor.”

This working agreement creates the potential for autonomy on the steelmaking side. “The first and foremost goal at the moment is for Hyundai Steel to supply automotive steel to Hyundai Motor,” Cho continues. “However, in the future, if Hyundai Steel makes enough automotive steel for Hyundai Motor, supplying automotive steel to other companies can be considered.”

Running at capacity

That level of capacity hasn’t been reached yet. Hyundai Steel is busy supplying some 80 grades of steel to its affiliate and has no current plans for joint projects with other automakers. [See Hyundai products sidebar, page 25.] And there are some unique alloys that are produced only for Hyundai Motor.

At this point, Hyundai Steel provides an average of 46 percent of all the steel used in Hyundai vehicles, including Class A outer body panels. The cost of shipping steel to plants outside of Korea necessitates buying some grades from local sources.

With operations in eight countries, Hyundai can stake a valid claim to being a global automaker. In addition to three plants in Korea with a combined capacity of 1.86 million units per year, the company maintains a North American assembly operation, Hyundai Motor Manufacturing Alabama. It‘s a $1.1 billion facility in Montgomery that opened in May 2005 and has a current annual capacity of 300,000 vehicles. There are also facilities in Brazil, the Czech Republic, Turkey, Russia, India and China. Combined annual production for these six plants is 2.35 million units, giving Hyundai a worldwide annual capacity of 4.51 million vehicles.

The flagship Dangjin steel mill is what Ahrens calls an “indoor” operation. “All the raw materials, including iron ore and coking coal, are stored indoors and transported in sealed conveyor belts,” he says. “Hyundai can tell its customers that much of the steel in their cars is made in as green a fashion as possible. No other carmaker can say this.”

HSLA and AHSLA steels at Hyundai predate the opening of the Dangjin mill. “[These materials] have been adapted to Hyundai automobiles since the end of the 1990s,” notes Cho. “For some special AHSLAs—such as 590 MPa (85,572 psi)—it would be early 2000s.”

Bake-hardened materials also are supplied by Hyundai Steel to both Hyundai and its subsidiary, Kia, for closure panels: doors, hoods and trunk lids. These metals gain tensile strength during the paint curing cycle with no other heat treating.

Tailor-welded blank technology is employed at Hyundai Motor to fabricate door inner panels. Sheet 0.7 millimeter thick (0.028 inch) is laser welded to 1.2-millimeter-thick (0.047-inch) stock before stamping to reduce assembly weight. According to Cho, weight of the door inners is reduced 5 percent, from 9.7 kilograms (21.4 pounds) per car to 9.3 kilograms (20.5 pounds). The number of components is cut from four to two, which also reduces cost.

High-tensile steels improve more than car performance; they also are a marketing advantage. “We are increasingly publicizing the use of Hyundai Steel in our vehicles,” Ahrens says, “and we will continue to do so. [see Elantra sidebar, page 26.] It is a competitive advantage that our competitors do not enjoy. Stay tuned to see what we do next.” MM

ELANTRA GT: 
60 PERCENT HIGH-TENSILE STEEL

At the 2012 Chicago Auto Show, Hyundai introduced the 2013 Elantra GT, a car with a manufacturer’s suggested list price of $19,395 but with a body-in-white containing 60 percent HSLA and AHSLA steels. In his presentation, Michael O’Brien, vice president of production and corporate planning, emphasized the weight-saving advantage of high-tensile steels.

At a base curb weight of 2,745 pounds for the manual transmission version, the four-door hatchback is claimed to be 151 pounds lighter than its nearest competitor. With a 1.8-liter four-cylinder engine producing 

148 horsepower, the GT is both a lively performer and seriously economical. The EPA rates it at 27 miles per gallon (city) and 39 miles per gallon (highway) with 87-octane regular gasoline. 

The television automotive magazine “MotorWeek” scored 33 miles per gallon in a combined city/highway driving test. “There is no big difference in the steel composition between low-cost cars and other higher-class cars regarding the adoption of [the higher performance] AHLSA,” says Hyundai Steel’s senior executive vice president Wonsuk Cho, Ph.D. “The composition of [advanced] steel grades for the Elantra is 21 percent."