Highway

Expressway, referred to as expressway, refers to a highway dedicated to high-speed driving of automobiles. As of December 28, 2018, the total mileage of expressways in China has reached 140,000 kilometers, ranking first in the world. The steel specifications for expressways are both Q235 and Q345.

(1) Q345 is a kind of steel material. It is a low-alloy steel, widely used in bridges, vehicles, ships, construction, pressure vessels, special equipment, etc. "Q" means the yield strength, and Q345 indicates that the yield strength of this steel is 345MPa.

(2) Q235 ordinary carbon structural steel is also called A3 plate, ordinary carbon structural steel-ordinary plate is a kind of steel material, Q represents the yield limit of this material, and the following 235 refers to this material The yield value is about 235MPa. And with the increase of the thickness of the material, the yield value will decrease. Due to the moderate carbon content, the comprehensive performance is better, the strength, plasticity and welding properties are better matched, and the use is the most extensive. There are also many standard parts used on highways. For example, guardrail bolts are important parts to connect these guardrails.