What is the q420a steel material?

Q420a material is a low-alloy high-strength structural steel, which is composed of Q+number+quality grade symbol+deoxidation method symbol. Its steel number is prefixed with "q", which represents the yield point of the q420a steel, and the following number represents the value of the yield point. The unit is known MPa. For example, q420 represents structural steel with a yield stress (σs) of 420 MPa.

The quality level is divided into A, B, C, D, and E, followed by the A grade with the poorer quality and the E grade with the highest quality. Respectively: q420a grade steel is not required for impact toughness test. The q420b level is for the impact toughness test at room temperature (20℃); the q420c level is for the 0℃ impact toughness test; the q420d level is for the -20℃ impact toughness test; the q420e is for the -40℃ impact toughness test. The impact toughness test uses Charpy V-notch specimens.