The second section our country steel grade expression method
First, our country steel grade expression method outline
The steel trademark abbreviation steel grade, is the name which takes to each kind of concrete steel product, is the people understands the steel one common language. Our country’s steel grade expression method, according to the national standards "Steel and iron Product Trademark Expressed that Method" (GB/T221-2000) stipulated that and started in November 1, 2000 to implement.
The product trademark’s expression, uses the method expression which generally the Chinese phonetic alphabet, the chemical element mark and the Arabic numeral unify. Namely:
①In the steel grade the chemical element uses the international chemical symbol to indicate that for example Si, Mn, Cr ......And so on. The misch metal element uses “RE” (or “Xt”) expressed.
②The product range, the use, smelting and the pouring procedure and so on, use the Pinyin the abbreviation letter to indicate generally,
③In the steel the main chemical element content (%) uses the Arabic numeral expression.
When uses Chinese phonetic alphabet expression product range, the use, the characteristic and the technique, generally from represents the product range in the Pinyin to select the first letter. When selects with another product when the letter is redundant, may change to the second letter or the third letter, simultaneously or selects in two Chinese characters the first pinyin alphabet.
Does not have the Chinese character which and the Pinyin temporarily may use, uses the mark for English letter.
Second, our country steel grade expression method classified explanation
1st, carbon structural steel and low-alloy high strength structure trademark expression method
The above usually divides into the general steel and the special-purpose steel two broad headings with the steel. The trademark expression method, by the steel yield point either yield strength’s Chinese phonetic alphabet, the yield point or the yield strength value, steel parts and so on quality scale is composed, but also some steel add the deaeration degree, is actually 4 parts composes.
①The general structural steel uses represents the yield point the pinyin alphabet “Q”. The yield point value (unit is the quality scale which MPa) and in table 1 stipulated (A, B, C, D, E), the deaeration method (F, b, Z, TZ) and so on marks, according to smooth composition trademark. For example: The carbon structural steel trademark expression is: Q235AF, Q235BZ; The low-alloy high-tensile structural steel trademark expression is: Q345C, Q345D.
Q235BZ expressed that the yield point value ≥235MPa, the quality scale is the B level calm carbon structural steel.
Q235 and Q345 these two trademarks are the project use the steel to be most typical, the production and the amount of use are biggest, use most widespread trademark. These two trademark various countries have nearly.
In the carbon structural steel’s trademark composition, the calm steel mark “Z” and the special calm steel mark “TZ” may abbreviate, for example: The quality scale respectively is the C level and D the level Q235 steel, its trademark expression should be Q235CZ and Q235DTZ, but may abbreviate is Q235C and Q235D.
The low-alloy high-tensile structural steel has the calm steel and the special calm steel, but the trademark rear part does not write the expression deaeration method the mark.
②The special-purpose structural steel uses generally represents representative who the steel yield point the mark “Q”, the yield point value and in table 1 stipulated product use expressions and so on mark, for example: The pressure vessel uses the steel trademark expression is “Q345R”; Bears the period of five days steel its trademark expression is Q340NH; The Q295HP welding air bottle uses the steel trademark; The Q390g boiler uses the steel trademark; The Q420q bridge uses the steel trademark.
③According to the need, the general low-alloy high-tensile structural steel’s trademark may also use two Arabic numerals (expression average carbon amount, by several ideas extremely) and chemical element mark, according to smooth expression; Special-purpose low-alloy high-tensile structural steel trademark, may also use two Arabic numerals (expression average carbon amount, by several ideas extremely) and the chemical element mark, as well as in table 1 stipulated that represents the product use the mark, according to smooth expression.
2nd, high quality carbon structural steel and high quality carbon spring steel trademark expression method
The high quality carbon structural steel uses two Arabic numerals (by extremely several to count the language synthesis trademark which expression average carbon amount) or the Arabic numeral and the symbols of the elements, in table 1 stipulated.
①The boiling steel and the semi-killed steel, add the mark separately in the trademark rear part “F” and “b”. For example: The average carbon amount is 0.08% boiling steel, its trademark expression is “08F”; The average carbon amount is 0.10% semi-killed steel, its trademark expression is “10b”.
②The calm steel (S, P distinguish ≤0.035%) generally not the sign mark. For example: The average carbon amount is 0.45% calm steel, its trademark expression is “45”.
③Compares Gao Hanmeng the quantity the high quality carbon structural steel, after expression average carbon amount Arabic numeral manganese addition symbols of the elements. For example: The average carbon amount is 0.50%, including the manganese quantity is 0.70%~1.00% steel, its trademark expression is “50Mn”.
④The high-quality high quality carbon structural steel (S, P distinguish ≤0.030%), in trademark add-on mark “A”. For example: The average carbon amount is 0.45% high-quality high quality carbon structural steel, its trademark expression is “45A”.
⑤Top grade high quality carbon structural steel (S≤0.020%, P≤0.025%), in trademark add-on mark “E”. For example: The average carbon amount is 0.45% top grade high quality carbon structural steel, its trademark expression is “45E”.
The high quality carbon spring steel trademark’s expression method and the high quality carbon structural steel trademark expressed that the method same (65, 70, 85, 65Mn steel simultaneously distinguish existence in GB/T1222 and in the GB/T 6992 standards).
3rd, alloy structural steel and alloy spring steel trademark expression method
①The alloy structural steel trademark uses the Arabic numeral and the standard chemical element symbolic representation.
With two Arabic numeral expression average carbon amount (by several ideas extremely), places the trademark forehead.
The alloying element content expression method is: When the average content is smaller than 1.50%, in the trademark only marks the element, generally does not mark the content; The average alloy content is 1.50%~2.49%, 2.50%~3.49%, 3.50%~4.49%, 4.50%~5.49%, ......, after alloying element wrote correspondingly 2, 3, 4, 5 .......
For example: The carbon, the chromium, the manganese, the silicon average content respectively is 0.30%, 0.95%, 0.85%, 1.05% alloy structural steel, when S, the P content distinguishes ≤0.035%, its trademark expression is “30CrMnSi”.
The high-quality high quality alloy structural steel (S, the P content distinguishes ≤0.025%), adds the mark in the trademark rear part “A” the expression. For example: “30CrMnSiA”.
The top grade high quality alloy structural steel (S≤0.015%, P≤0.025%), add the mark in the trademark rear part “E”, for example: “30CrM nSiE”.
The special-purpose alloy structural steel trademark still should, in the trademark forehead (or rear part) adds in table 1 to stipulate that represents the product use the mark. For example, the riveting spiral special-purpose 30CrMnSi steel, the steel grade expression is ML30CrMnSi.
②The alloy spring steel trademark’s expression method and the alloy structural steel is the same.
For example: The carbon, the silicon, the manganese average content respectively is 0.60%, 1.75%, 0.75% spring steel, its trademark expression is “60Si2Mn”. The high-quality high quality spring steel, adds the mark in the trademark rear part “A”, its trademark expression is “60Si2MnA”.
4th, easy to cut the steel trademark expression method
Easy to cut the steel to use the standard chemical element mark, Table 1 stipulation mark and the Arabic numeral expression. Arabic numeral expression average carbon amount (by several ideas extremely).
①The vulcanize easy to cut the steel and the vulcanize, the phosphorus easy to cut the steel, in mark “Y” after the Arabic numeral does not add easily to cut the symbols of the elements.
For example: The average carbon amount is 0.15% easy to cut the steel, its trademark expression is “Y15”.
②Compares Gao Hanmeng the quantity the vulcanize or the vulcanize, the phosphorus easy to cut the steel in the mark “Y” after the Arabic numeral manganese addition symbols of the elements. For example: The average carbon amount is 0.40%, including the manganese quantity is 1.20%~1.55% easy to cut the steel, its trademark expression is “Y40Mn”.
③Calcareous, the lead and so on easy to cut the element easily to cut the steel, “Y” add-on easy to cut the symbols of the elements in the mark with the Arabic numeral. For example: “Y15Pb”, “Y45Ca”.
5th, non-quenching and tempering mechanical structural steel trademark expression method
The non-quenching and tempering mechanical structural steel, adds the mark separately in the trademark forehead “YF” and “F” expressed that easy to cut the non-quenching and tempering mechanical structural steel and the hot forging uses the non-quenching and tempering mechanical structural steel, trademark expression method other contents and the alloy structural steel is the same. For example: “YF35V”, “F45V”

6th, tool steel trademark expression method
The tool steel divides into the ordinary tool steel, the alloy tool steel and the high-speed tool steel three kinds.
①The ordinary tool steel uses the standard chemical element mark, Table 1 stipulation mark and the Arabic numeral expression. Arabic numeral expression average carbon amount (by thousand point several idea).
a. contains the manganese quantity ordinary tool steel ordinary, after tool steel mark “T” for the Arabic numeral. For example: The average carbon amount is 0.80% ordinary tool steel, its trademark expression is “T8”.
b. compares Gao Hanmeng the quantity the ordinary tool steel, in tool steel mark “T” after the Arabic numeral manganese addition symbols of the elements. For example: “T8Mn”.
c. high-quality high quality ordinary tool steel, in trademark rear part Canada “A”. For example: “T8MnA”.
②Alloy tool steel and high-speed tool steel
The alloy tool steel, the high-speed tool steel trademark expression method and the alloy structural steel trademark expression method is the same. Uses the standing operating procedure the alloying element mark and the Arabic numeral indicated that but does not mark the average carbon amount digit generally, for example: The average carbon amount is 1.60%, chromic, the molybdenum, the vanadium content respectively is 11.75%, 0.50%, 0.22% alloy tool steels, its trademark expression is “Cr12MoV”; The average carbon amount is 0.85%, including the tungsten, the molybdenum, the chromium, the vanadium content respectively is 6.00%, 5.00%, 4.00%, 2.00% high-speed tool steels, its trademark expression is “W6Mo5Cr4V2”.
If the average carbon amount is smaller than time 1.00%, may use an Arabic numeral expression carbon amount (by thousand point several idea). For example: The average carbon amount is 0.80%, including the manganese quantity is 0.95%, including the silicon quantity is 0.45% alloy tool steel, its trademark expression is “8MnSi”.
The low chromium (average chromic quantity <1.00%) the alloy tool steel, (before thousand point several idea) adds the digit in the chromic quantity “0”. For example: The average chromic quantity is 0.60% alloy tool steel, its trademark expression is “Cr06”.
7th, plastic molding tool steel trademark expression method
Plastic molding tool steel trademark except, in the forehead adds the mark “SM” outside, other expression method and the high quality carbon structural steel and the alloy tool steel trademark expression method is the same. For example: The average carbon amount is 0.45% carbon plastic molding tool steel, its trademark expression is “SM45”; The average carbon amount is 0.34%, the chromic quantity is 1.70%, including the molybdenum quantity is 0.42% alloy plastic molding tool steel, its trademark expression is “SM3Cr2Mo”.
8th, bearing steel trademark expression method
The bearing steel divides into Gao Tange the bearing steel, the cementation bearing steel, Gao Tange the stainless bearing steel and the high temperature bearing steel and so on four broad headings.
①Gao Tange the bearing steel, adds the mark in the trademark forehead “G”, but does not mark the carbon amount. Chromium content by thousand point several idea, other alloying element according to alloy structural steel alloy content expression. For example: The average chromic quantity is 1.50% bearing steels, its trademark expression is “GCr15”.
②The cementation bearing steel, uses the alloy structural steel the trademark expression method, in addition adds the mark in the trademark forehead “G”. For example: “G20 CrNiMo”.
High-level high quality cementation bearing steel, in trademark rear part Canada “A”. For example: “G20CrNiMoA”.
③Gao Tange the stainless bearing steel and the high temperature bearing steel, use the stainless steel and the high-temperature steel trademark expression method, the trademark forehead do not add the mark “G”. For example: Gao Tange stainless bearing steel “9Cr18” and high temperature bearing steel “10Cr14Mo”.
9th, stainless steel and high-temperature steel trademark expression method
The stainless steel and the high-temperature steel trademark use the standing operating procedure the alloying element mark and the Arabic numeral indicated that to cut the stainless steel, easily to cut the high-temperature steel in trademark forehead Canada “Y”.
Generally expresses the average carbon amount with an Arabic numeral (by thousand point several idea); When average carbon amount ≥1.00%, expressed with two Arabic numerals; When carbon amount upper limit <0.10%, by “0” expression carbon amount; When carbon amount upper limit ≤0.03%, >0.01% (ultra low-carbon), by “03” expression carbon amount; When carbon amount upper limit (≤0.01% extremely low-carbon), by “01” expression carbon amount. When carbon amount stipulation lower limit, uses the Arabic numeral expression carbon amount the upper limit digit.
Alloying element content expression method with alloy structural steel. For example: The average carbon amount is 0.20%, the chromic quantity is 13% stainless steel, its trademark expression is “2Cr13”; The carbon amount upper limit is 0.08%, the average chromic quantity is 18%, including the nickel quantity is 9% chromated nickel stainless steel, its trademark expression is “0Cr18Ni9”; The carbon amount upper limit is 0.12%, the average chromic quantity is 17% vulcanize easy to cut the chromium stainless steel, its trademark expression is “Y1Cr17”; The average carbon amount is 1.10%, the chromic quantity is 17% Gao Tan the chromium stainless steel, its trademark expression is “11Cr7”; The carbon amount upper limit is 0.03%, the average chromic quantity is 19%, including the nickel quantity is 10% ultra low-carbon stainless steel, its trademark expression is “03Cr19Ni10”; The carbon amount upper limit is 0.01%, the average chromic quantity is 19%, including the nickel quantity is 11% side low-carbon stainless steel, its trademark expression is “01Cr19Ni11”.
The domestic present stainless high-temperature steel standard is refers to the JIS standard revision, but stainless high-temperature steel trademark country standard and so on an expression method and Japan are different. We are indicated with the alloying element and the average including the C quantity that Japan is with the expression use letter and the Arabic numeral expression. For example stainless steel trademark SUS202, SUS316, SUS430, S-steel (steel), U-use (use), S-stainless (stainless steel). For example high-temperature steel trademark, SUH309, SUH330, SUH660, H-Heatresistins. In trademark different digital presentation each different type stainless high-temperature steel. Japan expressed that stainless high-temperature steel each kind of different product, is on the trademark add-on corresponding letter, for example stainless steel rod SUS-B, hot rolling stainless steel plate SUS-HP; Heat-resisting steel rod SUHB, high-temperature sheet steel SUHP. Western countries and so on UK and US, stainless high-temperature steel trademark expression method with Japan basic consistent, is mainly indicated with the Arabic numeral, moreover expressed the digit is the same, namely the trademark is the same. Because Japan’s stainless high-temperature steel uses the US.
10th, weld steel trademark expression method
The weld steel including the welding with the carbon steel, the welding with the alloy steel and the welding with the stainless steel and so on, its trademark expressed that the method is adds the mark in each kind of weld steel trademark forehead “H”. For example: “H08”, “H08Mn2Si”, “H1Cr18Ni9”.
The high-quality high quality weld steel, adds the mark in the trademark rear part “A”. For example: “H08A”, “08Mn2SiA”.
11th, the electrician uses the silcon steel
The steel grade by the digit, the letter and the digit is composed.
Does not have the orientation and the orientation silcon steel alphabetic character respectively is” W” and” Q”
Front thickness places, among the alphabetic character places, behind the iron loss value places, for example 30Q113. In the orientation silcon steel, the high magnetic induction’s alphabetic character” G” and” Q” puts on the same place, for example 30QG113
After letter digital presentation iron loss value (W/kg) 100 times.
The letter “G”, expresses under the high-frequency examines; Has not added “G”, expressed is under 50 cycles examines in the frequency.
30Q113 expressed that the electrician uses the cold rolling orientation silcon steel product in 50 frequencies time biggest unit weight iron loss value is 1.13W/kg.
Cold rolling silcon steel expression method with the Japanese standard (JISC2552-86) consistent, is only the alphabetic character is different, for example orientation silcon steel trademark 27Q140, the JIS trademark which corresponds with it is 27G140,30QG110 with it corresponding JIS trademark is 30P110 (G: Expresses the ordinary material, P: Expresses the high orientation nature). Non-orientation silcon steel trademark 35W250, with it corresponding JIS trademark is 35A250.