Q245R(R-HIC) chemical composition and performance analysis
Q245R(R-HIC) Chemical Composition and Performance Analysis
Q245R(R-HIC) refers to the steel grade Q245R, where R-HIC stands for two kinds of corrosion experiments: one is sulfide stress corrosion test, referred to as SSCC, and the other is hydrogen-induced cracking resistance test referred to as HIC. In terms of P S content, it is required that the melting analysis P≤0.015, S≤0.003, the finished product analysis P≤0.015, S≤0.004, and the delivery state is normalized. Specimen condition: all steel plates should be simulated post-weld heat treatment for their test samples, the recommended simulated post-weld heat treatment temperature: 620±10 °C, holding time: 8 hours, the temperature above 400 °C is loaded into the furnace, and the temperature rise and fall speed ≤ 150 °C/h,
| Chemical composition |
| Tabulation: Depu Steel Date: 2024-01-18 |
| trademark |
category |
C |
Si |
Mn |
Al |
Ca* |
O* |
CE** |
| Q245R(R-HIC) |
Melting analysis |
≤0.20 |
≤0.35 |
0.50-1.00 |
≥0.020 |
0.0015-0.0030 |
≤0.004 |
≤0.36 |
| Finished product analysis |
≤0.40 |
0.45-1.05 |
Note:Finished product analysis ≤0.40 0.45-1.05
(1): The Ca value is for reference only, not as an acceptance condition, and the Ca and O content can be replaced by the 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 performance of the steel plate, some microalloying elements can be added.
It is smelted by electric furnace + external refining, and the smelting process is treated with Ca, and it should be an intrinsically fine-grained steel, and its actual grain size is grade 5 or above.
The delivery condition is normalized. Specimen status: all steel plates should be simulated post-weld heat treatment for their inspection samples, recommended simulated post-weld heat treatment temperature: 620±10 °C, holding time: 8 hours, temperature above 400 °C loading furnace, temperature rise and fall speed ≤ 150 °C/h, if inconsistent with the recommended heat treatment system, the specific simulation of post-welding heat treatment system is indicated in the contract.
The HIC test should be accepted in batches, and each batch is composed of steel plates with the same heat treatment system, the same heat treatment number, the same thickness, and the same heat treatment system. When the thickness is not more than 30mm, a group of samples is taken, and the sample size is plate thickness * 20mm * 100mm; When the thickness is greater than 30mm, a group of samples is taken from 1/2 of the thickness, and the sample size is 20mm*20mm*100mm.
