Importance of High-Strength Steel in Yard Ramp Construction
How is ASTM A572-50 plate steel manufactured?
ASTM (American Society for Testing and Materials) A572-50 plates are hot rolled structural steel with industry leading tolerance, concentricity, and straightness due to the addition of strong carbide and nitride formers that produce a small and fine grain, giving the best notch toughness. Each halving of the grain diameter produces a 50% increase in tensile strength.
ASTM A572-50 is an ultra-high strength, “workhorse” grade steel. Our bolted construction yard ramps are made from this all-American fully recyclable material and we pride ourselves on the superior workmanship and heavy-duty HSLA (High-Strength Low-Alloy Steel) construction. Our A572-50 ramps offer a minimum yield of 50,000 PSI and also boast significantly increased resistance to corrosion and 50ksi or 345 MPA minimum yield strength and 65ksi ultimate tensile strength. A572-50 steel is tailor made for our portable or mobile yard ramps, and our dock-to-ground ramps, where extra strength and reduced end product weight are paramount.
What is the blend of A572-50 plate steel?
ASTM A572-50 is a columbium and vanadium blend steel with trace elements of manganese, phosphorus, sulfur and silicon. Copper, silicon, nickel, and chromium are also added to ASTM A572-50 steel in our ramps, increasing corrosion resistance.
Columbium and vanadium are added for strengthening purposes and alter the microstructure of carbon steel plates, producing a fine dispersion of alloy carbides in an almost pure ferrite matrix. This eliminates the toughness-reducing effect of a pearlitic volume fraction, yet maintains and increases our ramps’ strength by refining the grain size. Due to this higher strength and toughness, our ASTM572-50 ramps require 25 to 30% more power to form, but that power translates into superior resilience and durability.
Are there special requirements for machining ASTM A572-50?
A572-50 HSLA steel is made to meet specific mechanical properties. A572-50 steel ramps have a carbon content between 0.05–0.25% that gives excellent formability and is an excellent material for strong and safe welds.
A572-50 HSLA steel is versatile and easy to cut. You can cut A572-50 with plasma, oxy-Acetylene, laser, water jet, and abrasive cut-off saws. Machining, drilling, countersinking, counterboring, tapping, milling, and general machining can also all be done with conventional equipment and carbide tools. A572-50 steel can be welded with simple procedures and common consumables such as E7018 welding rod.
Our A572-50 plate steel ramps are a little harder to form and a little heavier than aluminum but our steel yard ramps are the best option when you deal with heavy weights and if moving a slightly heavier ramp isn’t a concern.
Why we use A572-50 high strength steel on our yard ramps
As the industry leader in manufacturing and selling loading dock equipment, we insist on using the best material possible. A572-50 HSLA steel plates have a flat, clean surface, are stronger than mild steel, and provide incredibly high yield strength in a surprisingly light package. In permanent or moveable yard ramps where superior strength is required, a relatively light end product weight is a major plus.
A572 Grade 50 has a smaller cross-section that can support the same or larger load than A36 steel or steels that are not structural grade. This directly correlates to the overall weight of the ramp where the higher the steel’s Yield Strength, the less the ramp can weigh. A572 Grade 50 has a 139% greater Yield Strength than A36 steel.
A572 steel does not require preheat or post heating during the welding process and standard AWS D1.1 welding standards apply. Higher grades of steels will require preheating which is not economical compared to savings in weight. Welding wire for A572 Grade 50 that is used has a yield higher than the material. With stronger steels the welding wire yield strength begins to be closer to that of the steel. This makes the welds much more critical and provide less safety factor of the welds. As the steel increases in Yield and is designed as close to the safety factor as possible the deflection will increase. A ramp that deflects more moves more putting stresses on the concrete that it rests on, the trucks that it is supported by and also the chains that hold it to the trucks or docks. There is a point where the Yield strength of the steel cannot be taken advantage of because the deflection is too great. The use of A572 eliminates these problems.