Source of 16Mn grade forged material
Thread Content
Let’s discuss one question: What is the material standard for the billets used to manufacture 16Mn forgings for pressure vessels? It seems there are no steel billets, bars, or other forms of steel in the 16Mn grade. Please feel free to share your opinions actively
The old standard grade is what is now known as Q345, or Q355 once the new standard comes into effect next year
16Mn standard: 16Mn is the grade for low-alloy high-strength structural steel in the old national standard GB/T1591‑1988. In the new national standard GB/T1591‑2008, the corresponding grade is Q345 (Q345 has 5 quality grades, namely Q345A~Q345E); Q345A corresponds to the ASTM grade Gr·50 in the United States.
The past and present of 16Mn: It originated under the designation GB1591‑1988; in GB/T1591‑2008 it was renamed Q345; and in GB/T1591‑2018 it was upgraded to Q355 to align with international standards. :lol
Thank you all for your responses. I also carefully reviewed several versions of GB 1591, and now have a basic understanding of the origins of 16Mn material. I’m not sure about everyone else, but there are currently 3 issues: First, the material is Q345 or is about to be changed to Q355 – it is a low-alloy high-strength structural steel produced in accordance with GB/T1591 – and its chemical composition does not meet the requirements of the standard NB/T47008 for forgings used in pressure-bearing equipment. 2 refers to the low-alloy high-strength steel Q345 or Q355 produced by steel mills; it meets both the requirements of GB/T1591 and those of NB/T47008. However, when Q345 or Q355 is forged, it becomes 16Mn, and even the steel grade changes, which seems a bit strange. 3: If the steel is produced in accordance with GB/T1591, is it appropriate to specify 16Mn as the material grade in the steel warranty document?