What are the grading criteria for A/B/C/D/E?
Impact test temperatures decrease progressively, with low-temperature toughness increasing.
What are the applicable scenarios for Q345A?
Normal temperature, non-critical structures, no impact requirements (e.g., ordinary supports).
What are the applicable scenarios for Q345B?
Structures subjected to dynamic loads at normal temperature (+20℃) (factory beams and columns, ordinary bridges).
What are the applicable scenarios for Q345C/D?
Low-temperature environments (0℃/-20℃): Northern outdoor applications, pressure vessels, ships, cranes.
What are the applicable scenarios for Q345E?
Extremely cold regions (-40℃): High-altitude bridges, polar equipment, LNG storage tanks.