Introduction of Q235B steel grades
Carbon structural steel example:
Q235B (GB/T 700) Q is the yield strength of the first word 'yield' of the first letter of the hanyu pinyin; 235 refers to the yield strength of not less than 235Mpa; B refers to the grade of steel, (the grade of steel is divided into A, B, C, D level). Finally, you can also add the code for the way the steel is deoxidised, where: F for boiling steel, b for semi-sedated steel, Z for sedated steel, TZ for special sedated steel.
High quality carbon structural steel Example:
20 (GB/T 699) 20 refers to the average carbon content of 0.20% (expressed in parts per million). Example: 20Mn (GB/T 699) Mn refers to a higher alloying element containing manganese, the mass fraction of 0.70%-1.00%, listed separately. Example: 50MnA (GB / T 699) A indicates the metallurgical quality of steel. A for high-grade quality steel, E for special high-quality steel.
Pipe line steel example:
L245 (GB / T 9711) L is the first letter of the English pipeline word Line. 245 means that the minimum yield strength of not less than 245Mpa. Example: L290R (GB / T 9711) the last letter of the letter R indicates the state of delivery. R is rolled, N is normalised, Q is quenched + tempered, M is thermomechanically rolled. Example: L415QS (GB/T 9711) the last letter S indicates that the service conditions of the steel pipe for acidic media.
Seamless steel pipe for high pressure boiler Example:
12Cr1MoVG (GB 5310) 12 that contains about 0.12% of carbon, about 1% of chromium, moderate amounts of molybdenum and vanadium elements, the last letter G indicates that the steel for boiler steel.
Example of seamless steel pipe for low temperature piping:
16MnDG (GBT 18984) DG indicates that the low temperature pipeline.
Example of steel for pressure vessels:
15CrMoR (GB713) R indicates that the boiler and pressure vessel steel.
Stainless steel and heat-resistant steel
Carbon content with two- or three-digit Arabic numerals to indicate the carbon content of the best control value (in parts per million or parts per hundred thousand).
- 1. Only the upper limit of carbon content, when the upper limit of carbon content is not greater than 0.10%, the upper limit of 3/4 of the carbon content; when the upper limit of carbon content is greater than 0.10%, the upper limit of 4/5 of the carbon content.
- For example, if the upper limit of carbon content is 0.08%, the carbon content is expressed as 06; if the upper limit of carbon content is 0.20%, the carbon content is expressed as 16; if the upper limit of carbon content is 0.15%, the carbon content is expressed as 12.
- For ultra-low carbon stainless steel (i.e., carbon content is not greater than 0.030%), with three Arabic numerals to indicate the carbon content of the best control value (in parts per million).
- For example: the upper limit of carbon content of 0.030%, the carbon content of its grade to 022; carbon content of the upper limit of 0.020%, the carbon content of its grade to 015.
- 2. Specify the upper and lower limits, the average carbon content of X100. For example, if the carbon content is 0.16~0.25%, the carbon content in the grade is expressed as 20.
- Alloying element content of the chemical element symbols and Arabic numerals. Steel intentionally added niobium, titanium, zirconium, nitrogen and other alloying elements, although the content is very low, should also be marked in the grade.
- For example: carbon content of not more than 0.08%, chromium content of 18.00% ~ 20.00%, nickel content of 8.00% ~ 11.00% of stainless steel, grade 06Cr19Ni10.
- Carbon content of not more than 0.030%, chromium content of 16.00% ~ 19.00%, titanium content of 0.10% ~ 1.00% of the stainless steel, grade 022Cr18Ti.
- Carbon content of 0.15% ~ 0.25%, chromium content of 14.00% ~ 16.00%, manganese content of 14.00% ~ 16.00%, nickel content of 1.50% ~ 3.00%, nitrogen content of 0.15% ~ 0.30% of stainless steel, grade 20Cr15Mn15Ni2N.
- Carbon content of not more than 0.25%, chromium content of 24.00% ~ 26.00%, nickel content of 19.00% ~ 22.00% of heat-resistant steel, grade 20Cr25Ni20.