Q550NH weathering steel composition properties and welding performance

Q550NH weathering steel composition properties and welding performance

Q550NH weathering steel composition and welding performance
I. Q550NH steel plate introduction: 1. Q550NH steel plate grade representation method:
The steel grade is composed of "yield strength", "high weather resistance" or "weather resistance" in the first letter of Chinese pinyin "Q", "NH", the lower limit of yield strength and the quality grade (A, B, C, D, E).
For example: Q550NH
Q - the first letter of the Chinese pinyin of the word "yield" in yield strength;
550 - the lower limit of the yield strength of steel, in MPa;
NH - the first letter of the Chinese pinyin of the words "耐" and "候", respectively;
A, B, C, D, E – quality grades.
2. Q550NH steel plate implementation standard: GB/T 4171-2008.
3. The size, shape, weight and allowable deviation of Q550NH steel plate are implemented according to GB/T 709.
4. Q550NH steel plate smelting method: Q550NH is smelted by converter or electric furnace, and it is ** steel. Unless the buyer has special requirements, the smelting method is chosen by the supplier.
5. Q550NH steel plate delivery state: delivery in hot-rolled, controlled rolling or normalized state, can also be quenched and tempered in the state of delivery
 

Chemical composition

Tabulation: Depu Steel Date: 2024-01-18

C	Si	Mn	P	S	Cu	Cr	Ni
≤0.16	≤0.65	≤2.0	≤0.025	≤0.030	0.20-0.55	0.30-1.25	0.12-0.65

Note: a, in order to improve the performance of steel can add one or more trace alloying elements: Nb: 0.015% ~ 0.060%, V: 0.02% ~ 0.12%, Ti:
0.02% ~ 0.10%, Alt ≥ 0.020%, if the above elements are combined, at least one of the elements should be guaranteed to reach the lower limit of the above chemical composition.
b. The following alloying elements can be added: Mo≤0.30%, Zr≤0.15% c, Nb, V, Ti and other three alloying elements should not be added to the total amount of 0.22%

Sixth, Q550NH application range:
Corrosion resistance of Q550NH steel plate: Weathering steel is a steel that forms a protective layer on the surface of the metal matrix by adding a small amount of alloying elements such as: Cu, P, Cr, Ni, etc., so as to improve the atmospheric corrosion resistance. Q550NH steel is a welded weathering steel that is widely used in vehicles, bridges, containers, buildings or other structural parts. Compared with high weathering steel, it has better welding performance