SUBJECT: Advanced Steel

TOPIC: Extrication Challenges of Advanced Steel in Vehicles: Part 2

OBJECTIVE: The rescuer will understand and explain the rescue challenges presented by the introduction of advanced steels into the structure of late-model passenger vehicles.

TASK: Given the information contained in Part 2 of this series and reference to a late-model passenger vehicle, the rescuer will be able to identify potential areas of the vehicle where its structural steel is or could consist of "advanced steel."

We continue our discussion about the rescue challenges presented by the structural steel materials being used in the newest model-year vehicles. Automakers are working towards improving the side impact and rollover "crashworthiness" of their vehicles to comply with new government motor vehicle standards. In Part One of this series, we learned that there are two engineering solutions being employed; more and thicker steel or use of special alloys to create what is referred to as advanced steel. This second engineered solution — constructing areas such as B-pillars, roof rails, and rocker channels of ultra high-strength advanced steels — is the focus of this article.

To better understand what is different about these new advanced steels, we first need to understand what types of steels can be found in a passenger vehicle. Rescuers might find portions of a crash-damaged vehicle constructed of aluminum. This can include small components, a door panel or a hood for example, or possibly major structural portions of the vehicle such as the aluminum space-frame of the Audi A8.

Most often though, rescue personnel find that steel is what the vehicle is primarily made of. During rescue efforts, our extrication tools are able to bend, fold, or otherwise mutilate the common mild steel. Now however, with requirements for newer and more crashworthy vehicles, mild steel isn't the only type of steel we will encounter. Automakers over the past few years have introduced the use of stronger steels referred to as high-strength, low-alloy (HSLA) steels. HSLA steel is a tougher, more rescue tool cut-resistant metal. Our older hydraulic power cutters and our light-duty air chisel rescue tools will probably have difficulty working their way through HSLA metal pillars, roof rails, rockers, etc.