What is the Q420qD steel?

Q420qD grade steel is a structural steel plate for bridges, which is specified by the standard of GB/T 709.

Q420qD steel means:

Q represents the first letter of the Chinese Pinyin of "qu" which represents the yield strength of steel used in bridges;

420 represents the yield strength value, in MPa;

q represents the first letter of the Chinese pinyin of the word "Qiao" used for bridge steel;

D represents the D level of the quality level.

When the steel plate is required to have weather resistance or thickness direction performance, the Chinese pinyin letter "NH" representing weather resistance or the symbols Q420qD-Z15, Q420qD-Z25 in the thickness direction (Z direction) performance level shall be added after the above-mentioned grades respectively. Q420qD-Z35.

Q420qD steel is a structural steel plate for bridges. It is required to have high strength, toughness and bear the load and impact of rolling stock, and have good fatigue resistance, certain low temperature toughness and atmospheric corrosion resistance.