seamless tube

Q345A seamless tube grade, is not to do the impact. Q345B level, is the impact of 20 degrees at room temperature. Q345C level, is the impact of 0 degrees. Q345D level, is -20 degrees shock. Q345E level, is -40 degrees shock. At different impact temperatures, the values of the impact are also different. Q The yield strength is not less than 345Mp The quality grade indicates the amount of impurity elements (carbon, manganese, silicon, sulfur and phosphorus are impurity elements in steel), A, B, C, D The less