Side-impact car door beams in AHSS and UHSS grades

Side-impact beams and increased survival space

Side-impact automobile collisions, in general, result in more severe injuries than other types of collisions. Severe injuries to both upper and lower body can occur if the survival space is inadequate. Using optimized designs and advanced high strength steel grades for side-impact beams can significantly increase survival space in cars, helping to protect drivers and passengers during side impact crashes. 

Side-impact beams achieve 5-star crash performance – at a lighter weight

For a new design for side-impact car door beams, a Tier 1 supplier needed to improve crash test performance, corrosion resistance, and cost efficiency – while lowering weight. Aluminum proved to be too costly, while press hardening steel would require investments in hot-forming presses, as well as slower production times. 

Instead, the Tier 1 chose Docol^® CR1500M-EG in 1.0 mm thickness. The martensitic 1500 MPa side-impact beams helped the car achieve a 5-star crash safety rating for side impacts while their 1.0 mm thickness kept the car door light in weight. Plus, the electrogalvanized metal coating provides the required level of corrosion resistance at a cost-efficient price point.

The Docol^® CR 1200Y 1500T-MS-EG side-impact beam is cold stamped, saving production time, cost and emissions compared to hot stamping. A 3-point bending test verifies how the side-impact beam will perform during a crash, demonstrating the ability to deform without cracking. Image courtesy of KIRCHHOFF Automotive.

Waistline car door beam in HR700LA-GI steel meets global crash tests

This new design for waistline car door side reinforcement features a roll-formed, laser-welded, closed profile beam in hot-dip galvanized Docol^® HR700LA-GI. The waistline beam is either 2.0 mm or 3.0 mm thick, depending on the car model. With the high-strength, low-alloy (HSLA) 700 MPa steel, the waistline reinforcement beam achieves 5-star crash test performance and fulfills all current global automotive safety requirements.

Another example of roll-forming AHSS steel into innovative safety profiles: This car door waistline reinforcement beam in Docol^® HR700LA-GI features low weight, hot-dip galvanized corrosion resistance, and 5-star crash performance.

Cold stamping 1400 MPa martensitic steel for side-impact car door beams

The existing design for this side-impact car door beam used CR1200M-EG. To further improve its crash performance and to reduce weight, the OEM is doing trial stamping of Docol^® CR1400M-EG in 1.3 mm thickness. In addition to achieving 5-star crash test performance, the beam can be stamped using conventional cold stamping processes, achieving better cost and energy efficiencies compared to hot-stamping or using aluminum.

Side-impact car door beam in Docol^® CR1400M-GI: a cold-stamped, corrosion-resistant, cost-efficient solution.