What is S420N low alloy high strength steel plate

We can regard S420N low alloy high strength steel plate as low alloy high strength steel. Q420 is equal to S420N low alloy high strength steel plate.S420N low alloy high strength steel plate is a class of weldable low carbon engineering structural steel. carbon content of S420N low alloy high strength steel plate /sheet is usually less than 0.25%, than the ordinary carbon structural steel has a higher yield σs or yield strength σ0.2 (30 ~ 80kgf / mm2) and yield ratio σs / σb (0.65 ~ 0.95), better Hot and cold forming process ability, good weldability, low brittle tendencies, notch and aging sensitivity, as well as better resistance to atmospheric, sea and other corrosion.