Quenching + tempering Q890D steel plate

Q890D steel plate ultrasonic inspection:
Standard for ultrasonic inspection of Q890D steel plate: GB/T 2970-2004. This standard specifies the comparative samples for ultrasonic inspection of thick steel plates, inspection instruments and equipment, inspection conditions and methods, determination and evaluation of defects, quality grading of steel plates, inspection reports, etc.

Q890D steel plate technical standard: GB/T 16270-2009.
Q890D steel plate delivery status: quenching + tempering (Q+T).

Chemical composition of Q890D steel plate:

Grade

C

Si

Mn

P

S

Ni

Cr

Mo

Cu

Nb

V

Ti

B

Q890D

≤0.2

≤0.8

≤2

≤0.025

≤0.015

≤2

≤1.5

≤0.7

≤0.5

≤0.06

≤0.12

≤0.05

≤0.005

Composition Remarks: At least one grain refinement element of Nb, Ti, V, Al is added to the steel, and the minimum amount of at least one element is 0.015 (Als for Al). Alt can be used instead of Als, in this case Alt ≥ 0.018. Ceq = C+Mn/6+(Cr+Mo+V)/5+(Ni+Cu)/15

Mechanical properties of Q890D steel plate:

Thickness	Mechanical properties
≤50mm	ReH(MPa)	≥890	When the yield is not obvious, use Rp0.2
	Rm(MPa)	940-1100
	A(%)	≥11
	Impact temperature	-20
	Akv(J)	≥34	Longitudinal
>50-100mm	ReH(MPa)	≥830	When the yield is not obvious, use Rp0.2
	Rm(MPa)	880-1100
	A(%)	≥11
	Impact temperature	-20
	Akv(J)	≥34	Longitudinal

Q890D steel smelting method:
Converter / electric furnace steelmaking → LF furnace refining → VD furnace vacuum degassing → continuous casting / die casting / electroslag → cleaning and heating → rolling → flaw detection → heat treatment → steel plate finishing → sampling → performance inspection