Comparison of Q245R, ASTM A516 grade 70, Q345R

ASTM A516 Grade 70 Pressure Vessel And Boiler Steel Plate is used in Pressure Vessel,Boiler,Storage Tanks and Heat Exchange.

The strength of ASTM A516 grade 70 is slightly higher than Q245R, Close to but a bit lower than Q345R.

Most smelter in China, choose Q245R as the manufacturing material. Firstly, Q245R has less welding defects than Q345R, which is determined by its chemical composition. In addition, Q245R is better than Q345R in hydrogen corrosion resistance.

The main chemical elements affecting the corrosion of hydrogen sulfide are Mn and s. In the process of steel production and equipment welding, manganese produces high strength and low toughness microstructure of martensite / bainite, which shows extremely high hardness, which is extremely unfavorable for the equipment to resist hydrogen sulfide corrosion. In addition, non-metallic inclusions of manganese sulfide and iron sulfide are formed in the steel, resulting in local microstructure loosening and stress corrosion in wet hydrogen sulfide environment.

Table1 Chemical Composition

Table2 Mechanical Property

Note: HIC resistant steel plate (hydrogen sulfide corrosion resistant steel plate):

1. Low P and S content, good resistance to wet hydrogen sulfide corrosion;

2. Hydrogen-induced cracking (HIC) performance test, the test method is in accordance with NACE TM0284 standard or GB/T 8650;

3. Excellent resistance to sulfide stress corrosion (SSCC) performance.