1. Scope of application of Q245R (HIC) (R-HIC) Q345R (HIC) (R-HIC) steel plate
This technical condition is suitable for the use of 8mm-150mm Q245R (HIC), Q245R (R-HIC) steel plate and Q345R (HIC), Q345R (R-HIC) steel plate in acidic environment. The grades of hydrogen sulfide corrosion resistant steel plate added to SSCC inspection items are expressed by Q245R (R-HIC) and Q345R (R-HIC).
In order to meet the different requirements of users and facilitate production management, the S and P requirements of steel grades are divided into three levels: I, II and III.
2. Q245R (HIC) (R-HIC) Q345R (HIC) (R-HIC) plate number Description
Q245R (HIC) -I refers to grade Q245R of steel. Corrosion test only conducts hydrogen induced cracking test (HIC). Composition requirements are melting analysis P < 0.015, S < 0.003, and finished product analysis P < 0.015, S < 0.004.
Q245R (R-HIC) -I refers to the grade of steel Q245R, which is tested by hydrogen induced cracking test (HIC) and sulfide stress corrosion test (SSCC). Its composition requires melting analysis P < 0.015, S < 0.003, and finished product analysis P < 0.015, S < 0.004.
Size, shape, weight and allowable deviation
2.1 The size, shape, weight and allowable deviation of steel plate shall comply with GB/T709.
2.2 Thickness deviation shall be executed in Class B or C of GB/T709 and shall be specified in the contract.
2.3 Steel plates are delivered according to theoretical weight. The thickness of theoretical weight is the arithmetic average of maximum allowable thickness and minimum thickness of steel plates. The density of steel is 7.85g/cm3.
3.Q245R (HIC) (R-HIC) Q345R (HIC) (R-HIC) Steel Plate Technical Requirements
3.1 Chemical Constituents
The chemical composition of the steel shall conform to Table 1 and 2.
Steel grade C Si Mn AL Ca*O*CE**
Analysis of Q245R (HIC) Q245R (R-HIC) Smelting (< HIC)
Zero point two zero
Less than
0.35 0.50-
1.00 (> 0.020) 0.0015-
0.0030 < 0.004 < 0.004 < 0.0030
Zero point three six
Finished product analysis <0.40 0.45-
One point zero five
Melting Analysis of Q345R (HIC) Q345R (R-HIC) Less than 0.20 0.20-0.55 1.20-
1.36 (> 0.020)
0.0015-
0.0030 < 0.004 < 0.45
Finished product analysis 0.20-0.60
Table 1
Note: (1) Ca value is only for reference, not for acceptance condition. Ca and O content can be replaced by melting analysis value by finished product analysis value.
(2) The formula for calculating carbon equivalent (CE) is as follows: CE=C+Mn/6+(Cu+Ni)/15+(Cr+Mo+V)/5.
(3) In order to improve the properties of steel plate, some microalloying elements can be added.
Table 2
Grade Component P S
I. Melting <0.015 <0.003
Finished products < 0.015 < 0.004
II. Melting <0.010 <0.002
Finished products < 0.010 < 0.003
III. Melting <0.008 <0.002
Finished products < 0.008 < 0.002
3.2 Smelting Method
In the process of smelting, Ca treatment should be carried out in the way of EAF + off-furnace refining, and the steel should be fine grained in nature, with the actual grain size of grade 5 or more.
3.3 Delivery Status: Normalizing.
3.4 Sample State: All steel plates shall be treated by simulated post-weld heat treatment for their test specimens. It is recommended that simulated post-weld heat treatment temperature be 620 (+10 C), holding time be 8 hours, temperature be over 400 (?) and heating and cooling rate be less than 150 (?) H. If it is not in conformity with the recommended heat treatment system, the simulated post-weld heat treatment system should be injected into the contract. Ming.
3.5 Mechanical Properties
3.5.1 The mechanical properties of simulated post-weld heat treatment of steel plate specimens shall conform to the requirements of the table below.
Table 3
Steel grade thickness
(mm) ReL
MPa Rm
MPa A
% Impact temperature
Temperature Impact Value
J 180 Degree Bending Test
B=2a Thickness Direction Performance Z(%)
Average value
Q245R (HIC)
Q245R (R-HIC) 8-16 (> 245 400-520 (> 25-20) Means (> 34 singletons (> 24 d = 1.5a)
More than 35
More than 25
> 16-36 (> 235)
> 36-60 (> 225)
> 60-100>205 390-510>24 d=2a
> 100-150 (> 185) 380-500
Q345R (HIC)
Q345R (R-HIC) 8-16 (> 345 510-640)
Over 21-30
Mean value (> 34 single value (> 24 d = 2a)
More than 35
More than 25
> 16-36 (> 325 500-630) d = 3A
> 36-60 (> 315, 490-620)
> 60-100 (> 305) 490-620 (> 20)
> 100-150 (> 285) 480-610
Note: (1) Thickness direction performance of steel plate with thickness (> 15mm);
3.5.2 Brinell hardness: The steel plate shall be tested for Brinell hardness by rolling tension, and the Brinell hardness value is less than 200 HB.
3.6 Ultrasound Inspection: The steel plate shall be inspected one by one, and the standard level of inspection shall be indicated in the contract.
3.7 The inspection items, sampling quantity, sampling methods and test methods of each batch of steel plates shall conform to Table 4.
Table 4
Inspection Items, Sampling Quantity (Number) Sampling Method, Test Method
Chemical analysis * smelting analysis 1 (per furnace) GB/T 20066 GB/T223
* Finished product analysis 1 (rolling by rolling)
Tension 1 (rolling by rolling) GB/T 2975 GB/T 228
Bending 1 (rolling by rolling) GB/T 2975 GB/T 232
Thickness Directional Performance 3 (Rolling-by-Rolling) GB/T5313 GB/T5313
Grain Size 1 (per furnace) YB/T5148-93
Brinell hardness 1 (roll-by-roll) GB/T 231
Ultrasound Flaw Detection Contract by Contract
* HIC test as specified in the contract
Impact 3 (roll-by-roll) GB/T 2975 GB229
* High Temperature Tension 1 (Rolling by Rolling)
See additional requirements GB/T 2975 GB/T 4338
The contract states
* SSCC Test as specified in the Contract
Note: Tape * is an optional item.
4. Q245R (HIC) (R-HIC) Q345R (HIC) (R-HIC) Steel Plate Inspection Rules
4.1 The surface quality of steel plate shall conform to the requirements of GB713-2014.
4.2 The packing, marking and quality certificate of the steel plate shall comply with the requirements of GB713-2014.
4.3 Implementing the provisions of GB713-2014
Additional requirements (guaranteed only when the user makes a request and is specified in the contract)
1. Simulated post-weld heat treatment system
2. High Temperature Tensile (Negotiated by Both Parties)
3. Low Temperature Shock (Negotiation)
4. Inspection Rules for Hydrogen Induced Crack Resistance (HIC) Test of Steel Plates
A. Test methods for hydrogen induced cracking (HIC), one of which is optional.
(1) Implementation of NACE TM0284 standard, using solution A, the average values of three samples are: CLR < 10%; CSR < 3%; CTR < 1%.
(2) Implementation of NACE TM0284 standard, using B solution, the average values of three samples are: CLR < 10%; CSR < 3%; CTR < 1.5%.
(3) Implementation of GB8650 standard, using A solution, the average values of three samples are: CLR < 10%; CSR < 3%; CTR < 1.5%.
(4) Implementing GB8650 standard, using B solution, the average values of three samples are: CLR < 10%; CSR < 3%; CTR < 1.5%.
PH: medium acidity and basicity; CLR: percentage of crack length; CSR: percentage of crack sensitivity; CTR: percentage of crack thickness
B. HIC Test Acceptance Rules
HIC test shall be checked and accepted in batches, each batch consisting of steel plates of the same furnace number, thickness and heat treatment system. When the thickness is not more than 30 mm, a group of specimens is taken. The size of the specimens is * 20 mm * 100 mm. When the thickness is more than 30 mm, a group of specimens is taken from 1/2 of the thickness. The size of the specimens is 20 mm * 20 mm * 100 mm.
Test Rules for Sulfide Stress Corrosion Resistance of 5.Q245R (HIC) (R-HIC) Q345R (HIC) (R-HIC) Steel Plates
A. Sulfide Stress Corrosion Resistance (SSCC) Test Method, one of which is optional
(1) Implement GB4157 standard.
(2) Implementation of NACE TM0177 Standard
B. SSCC Test Acceptance Rules
Q245R (R-HIC) threshold stress (> 180 MPa), Q345R (R-HIC) threshold stress (> 230 MPa), SSCC test shall be accepted in batches. A batch of steel plates with the largest thickness in the same contract number shall be selected and a group of samples shall be taken from a thickness of 1/2.