The surface of the Q460C steel plate should not have harmful defects such as air bubbles, scars, cracks, folds, inclusions, and pressed iron oxide scales that affect the use. Q460C steel plate should not have visually visible delamination. The surface of the Q460C steel plate is allowed to have a thin layer of iron oxide scale, rust that does not hinder the inspection of surface defects, and inconspicuous roughness, reticulation, pitting, scratches and other local defects caused by pressing the iron oxide scale and rolls, but the depth is not limited. It should be greater than half of the tolerance of the thickness of the steel plate, and the minimum thickness allowed by the Q460C steel plate should be guaranteed.
The surface defects of the steel plate can be removed by grinding and other methods. The cleaned place should be smooth without edges and corners. The cleaning depth should not be greater than the negative deviation of the steel plate thickness, and the minimum thickness allowed for the steel plate should be guaranteed.
Welding and repairing of Q460C steel plate shall adopt appropriate welding method. Before welding repair, use appropriate methods such as shoveling or grinding to completely remove harmful defects on the steel plate. The depth of the removed part should be within 20% of the nominal thickness of the steel plate, and the total grinding area on one side should be within 2% of the steel plate area.
There shall be no undercut or overlap on the edge of the welding part of Q460C steel plate, and the pile height shall be more than 1.5mm higher than the rolling surface, and then the pile height shall be removed by shoveling or grinding; the heat treatment of Q460C steel plate shall be heat treated again after welding and repairing. The surface quality of Q460C steel plate can also meet the requirements of GB/T14977.
Q460C steel plate is used as high-strength steel structural parts for engineering and general structures with impact performance requirements at low temperature. It is mainly used in the manufacture of bridges, ships, vehicles, boilers, high-pressure vessels, oil and gas pipelines, large steel structures, etc.
