Alloy Steel

The inner world of metal

Definition of Alloy Steel

In addition to iron and carbon, alloy steel is called alloy steel by adding other alloying elements. An iron-carbon alloy formed by adding an appropriate amount of one or more alloying elements on the basis of ordinary carbon steel. According to the difference of added elements and appropriate processing technology, special properties such as high strength, high toughness, wear resistance, corrosion resistance, low temperature resistance, high temperature resistance, and non-magnetic properties can be obtained.

The most important and desirable changes to alloy steel are:

*Enhanced hardenability.

*Enhanced corrosion resistance.

*Maintain hardness and strength.

*Almost all alloy steels require heat treatment to achieve their optimum properties.

 

Alloy Steel Schematic diagram of the internal structure of alloy steel

Generation and development of alloy steel

Alloy steel has a history of more than 100 years. More industrial use of alloy steel was about the second half of the 19th century.

In 1868, the British R.F.Mushet invented a self-hardening steel with a composition of 2.5%Mn-7%W, which increased the cutting speed to 5 m/min.

In 1870, a bridge with a span of 158.5 meters was built on the Mississippi River with chromium steel (1.5-2.0%Cr) in the United States; later, some industrial countries switched to nickel steel (3.5%Ni) to build long-span bridges, or used for Build warships.

In 1901, high carbon chromium rolling bearing steel appeared in Western Europe.

In 1910, 18W-4Cr-1V high-speed tool steel was developed, which further increased the cutting speed to 30 m/min.

After the 1920s, stainless steel and heat-resistant steel were introduced during this period.

In 1920, the German E. Maurer invented the 18-8 type stainless acid-resistant steel.

Fe-Cr-Al resistance wire appeared in the United States in 1929.

In 1939, Germany began to use austenitic heat-resistant steel in the power industry.

 

After World War II to the 1960s, it was mainly the era of developing high-strength steel and ultra-high-strength steel. Due to the needs of the aviation industry and the development of rocket technology, many new types of high-strength steel and ultra-high-strength steel appeared, such as Precipitation hardening high-strength stainless steel and various low-alloy high-strength steels are its representative steel grades. After the 1960s, many new metallurgical technologies, especially the out-of-furnace refining technology, were widely used, and alloy steel began to develop in the direction of high purity, high precision and ultra-low carbon, and maraging steel and ultra-pure ferrite appeared. Stainless steel and other new steel grades.

There are thousands of alloy steel grades and tens of thousands of specifications used internationally. The output of alloy steel accounts for about 10% of the total steel output. It is an important metal material widely used in national economic construction and national defense construction.

Since the 1970s, the development of alloyed high-strength steels in the world has entered a new period. Based on the controlled rolling technology and the metallurgy of microalloying, the modern low-alloyed high-strength steels, namely microalloyed steels, have been formed. new concept.

In the 1980s, a variety development involving a wide range of industrial fields and specialized material categories reached its peak with the help of achievements in metallurgical process technology. In the four-in-one relationship of chemical composition-process-structure-property of steel, the dominance of the microstructure and microstructure of steel is highlighted for the first time, and it also shows that the basic research of low-alloy steel has become mature, with unprecedented A new concept for alloy design

The inner world of alloy steel materials

Classification of alloy steel

  1. According to the content of alloying elements

      1) Low alloy steel – the total content of alloying elements is less than or equal to 5%

      2) Medium alloy steel – the total content of alloying elements is between 5% and 10%

      3) High alloy steel – the total content of alloying elements is greater than or equal to 10%

  1. According to the type of alloying elements

      1) Chrome steel

      2) Manganese steel

      3) chrome manganese steel

      4) Chrome Nickel Steel

      5) chrome nickel molybdenum steel

      6) Silicon manganese molybdenum vanadium steel, etc.

  1. According to the main purpose

      1) Structural steel

      2) Tool steel

      3) Special performance steel

There are many types of alloy steel, usually divided into low alloy steel (content <5%), medium alloy steel (content 5% ~ 10%), high alloy steel (content> 10%) according to the content of alloying elements; according to quality, it is divided into high-quality steel Alloy steel, special alloy steel; according to characteristics and uses, it is divided into alloy structural steel, stainless steel, acid-resistant steel, wear-resistant steel, heat-resistant steel, alloy tool steel, rolling bearing steel, alloy spring steel and special performance steel (such as soft magnetic steel). , permanent magnet steel, non-magnetic steel) and so on.

The alloy steel systems of various countries vary according to their respective resource conditions, production and use conditions. Some countries have developed nickel steel and steel systems in the past, while my country has found that silicon, manganese, vanadium, titanium, niobium, boron, lead, Rare earth based alloy steel system. Alloy steel accounts for about ten percent of the total output of steel, and is generally smelted in electric furnaces. Alloy steels can be divided into 8 categories according to their uses. They are: alloy structural steel, spring steel, bearing steel, alloy steel Tool steel, high-speed tool steel, stainless steel, heat-resistant non-skin steel, silicon steel for electrical use.

Our classification of alloy steels:

  1. Quenched and tempered steel

    1) Medium carbon alloy steel with low alloying element content;

    2) High strength;

    3) Used for high temperature bolts, nut materials, etc. [8]

 

  1. Spring steel

    1) The carbon content is higher than that of quenched and tempered steel;

    2) After quenching and tempering treatment, the strength is higher and the fatigue resistance is higher;

    3) For spring material.

 

  1. Rolling bearing steel

    1) High carbon alloy steel with high alloy content;

    2) It has high and uniform hardness and wear resistance;

    3) For rolling bearings.

 

  1. Alloy tool steel – also known as measuring tool steel

    1) High carbon alloy steel with low content of alloying elements;

    2) It has high hardness and wear resistance, good machining performance and good stability;

    3) For measuring tool materials.

 

  1. Special performance steel

    1) Low carbon high alloy steel;

    2) Good corrosion resistance;

    3) For anti-corrosion, some can be used as heat-resistant materials.

 

  1. Heat-resistant steel

    1) Low carbon high alloy steel;

    2) Good heat resistance; 3

For heat-resistant materials, some can be used as anti-corrosion materials.

 

  1. Low temperature steel

    1) Low carbon alloy steel, according to the degree of low temperature resistance, the alloy elements are high or low;

    2) Good low temperature resistance;

    3) For low temperature materials (special steel is nickel steel).

The combination of elements in the alloy

Comparison table of commonly used alloy grades

 

Grade China Russia America British Japan French Germany
GB ГОСТ ASTM BS JIS NF DIN
High quality carbon structural steel 08F 08КП 1006 040A04 S09CK C10
8 8 1008 045M10 S9CK C10
10F 1010 040A10 XC10
10 10 1010/1012 045M10 S10C XC10 C10,CK10
15 15 1015 095M15 S15C XC12 C15,CK15
20 20 1020 050A20 S20C XC18 C22,CK22
25 25 1025 S25C CK25
30 30 1030 060A30 S30C XC32
35 35 1035 060A35 S35C XC38TS C35,CK35
40 40 1040 080A40 S40C XC38H1
45 45 1045 080M46 S45C XC45 C45,CK45
50 50 1050 060A52 S50C XC48TS CK53
55 55 1055 070M55 S55C XC55
60 60 1060 080A62 S58C XC55 C60,CK60
15Mn 15Г 1016/1115 080A17 SB46 XC12 14Mn4
20Mn 20Г 1021/1022 080A20 XC18
30Mn 30Г 1030/1033 080A32 S30C XC32
40Mn 40Г 1036/1040 080A40 S40C 40M5 40Mn4
45Mn 45Г 1043/1045 080A47 S45C
50Mn 50Г 1050/1052 030A52 S53C XC48
080M50
Alloy Structural Steel 20Mn2 20Г2 1320/1321 150M19 SMn420 20Mn5
30Mn2 30Г2 1330 150M28 SMn433H 32M5 30Mn5
35Mn2 35Г2 1335 150M36 SMn438(H) 35M5 36Mn5
40Mn2 40Г2 1340 SMn443 40M5
45Mn2 45Г2 1345 SMn443 46Mn7
50Mn2 50Г2 ~55M5
20MnV 20MnV6
35SiMn 35CГ En46 37MnSi5
42SiMn 35CГ En46 46MnSi4
40B TS14B35
45B 50B46H
40MnB 50B40
45MnB 50B44
15Cr 15X 5115 523M15 SCr415(H) 12C3 15Cr3
20Cr 20X 5120 527A19 SCr420H 18C3 20Cr4
30Cr 30X 5130 530A30 SCr430 28Cr4
35Cr 35X 5132 530A36 SCr430(H) 32C4 34Cr4
40Cr 40X 5140 520M40 SCr440 42C4 41Cr4
45Cr 45X 5145/5147 534A99 SCr445 45C4
38CrSi 38XC
12CrMo 12XM 620Cr.B 12CD4 13CrMo44
15CrMo 15XM A-387Cr. B 1653 STC42 12CD4 16CrMo44
STT42
STB42
20CrMo 20XM 4119/4118 CDS12 SCT42 18CD4 20CrMo44
CDS110 STT42
STB42
25CrMo 4125 En20A 25CD4 25CrMo4
30CrMo 30XM 4130 1717COS110 SCM420 30CD4
42CrMo 4140 708A42 42CD4 42CrMo4
708M40
35CrMo 35XM 4135 708A37 SCM3 35CD4 34CrMo4
12CrMoV 12XMΦ
12Cr1MoV 12X1MΦ 13CrMoV42
25Cr2Mo1VA 25X2M1ΦA
20CrV 20XΦ 6120 22CrV4
40CrV 40XΦA 6140 42CrV6
50CrVA 50XΦA 6150 735A30 SUP10 50CV4 50CrV4
15CrMn 15XГ,18XГ
20CrMn 20XГCA 5152 527A60 SUP9
30CrMnSiA 30XГCA
40CrNi 40XH 3140H 640M40 SNC236 40NiCr6
20CrNi3A 20XH3A 3316 20NC11 20NiCr14
30CrNi3A 30XH3A 3325 653M31 SNC631H 28NiCr10
3330 SNC631
20MnMoB 80B20
38CrMoAlA 38XMIOA 905M39 SACM645 40CAD6.12 41CrAlMo07
40CrNiMoA 40XHMA 4340 871M40 SNCM439 40NiCrMo22
Spring steel 60 60 1060 080A62 S58C XC55 C60
85 85 C1085 080A86 SUP3
1084
65Mn 65Г 1566
55Si2Mn 55C2Г 9255 250A53 SUP6 55S6 55Si7
60Si2MnA 60C2ГA 9260 250A61 SUP7 61S7 65Si7
9260H
50CrVA 50XΦA 6150 735A50 SUP10 50CV4 50CrV4
Rolling bearing steel GCr9 ШX9 E51100 SUJ1 100C5 105Cr4
51100
GCr9SiMn SUJ3
GCr15 ШX15 E52100 534A99 SUJ2 100C6 100Cr6
52100
GCr15SiMn ШX15CГ 100CrMn6
Free cutting steel Y12 A12 C1109 SUM12
Y15 B1113 220M07 SUM22 10S20
Y20 A20 C1120 SUM32 20F2 22S20
Y30 A30 C1130 SUM42 35S20
Y40Mn A40Г C1144 225M36 45MF2 40S20
Wear-resistant steel ZGMn13 116Г13Ю SCMnH11 Z120M12 X120Mn12
T7 y7 W1-7 SK7,SK6 C70W1
Carbon Tool Steel T8 y8 SK6,SK5
T8A y8A W1-0.8C 1104Y175 C80W1
T8Mn y8Г SK5
T10 y10 W1-1.0C D1 SK3
T12 y12 W1-1.2C D1 SK2 Y2 120 C125W
T12A y12A W1-1.2C XC 120 C125W2
T13 y13 SK1 Y2 140 C135W
Alloy Tool Steel 8MnSi C75W3
9SiCr 9XC BH21 90CrSi5
Cr2 X L3 100Cr6
Cr06 13X W5 SKS8 140Cr3
9Cr2 9X L 100Cr6
W B1 F1 BF1 SK21 120W4
Cr12 X12 D3 BD3 SKD1 Z200C12 X210Cr12
Cr12MoV X12M D2 BD2 SKD11 Z200C12 X165CrMoV46
9Mn2V 9Г2Φ 2 80M80 90MnV8
9CrWMn 9XBГ 1 SKS3 80M8
CrWMn XBГ 7 SKS31 105WC13 105WCr6
3Cr2W8V 3X2B8Φ H21 BH21 SKD5 X30WC9V X30WCrV93
5CrMnMo 5XГM SKT5 40CrMnMo7
5CrNiMo 5XHM L6 SKT4 55NCDV7 55NiCrMoV6
4Cr5MoSiV 4X5MΦC H11 BH11 SKD61 Z38CDV5 X38CrMoV51
4CrW2Si 4XB2C SKS41 40WCDS35-12 35WCrV7
5CrW2Si 5XB2C S1 BSi 45WCrV7
High speed tool steel W18Cr4V P18 T1 BT1 SKH2 Z80WCV S18-0-1
2018/4/1
W6Mo5Cr4V2 P6M3 N2 BM2 SKH9 Z85WDCV S6-5-2
06-05-04-02
W18Cr4VCo5 P18K5Φ2 T4 BT4 SKH3 Z80WKCV S18-1-2-5
18-05-04-01
W2Mo9Cr4VCo8 M42 BM42 Z110DKCWV S2-10-1-8
09-08-04-02-01
Stainless Steel 1Cr18Ni9 12X18H9 302 302S25 SUS302 Z10CN18.09 X12CrNi188
S30200
Y1Cr18Ni9 303 303S21 SUS303 Z10CNF18.09 X12CrNiS188
S30300
0Cr19Ni9 08X18H10 304 304S15 SUS304 Z6CN18.09 X5CrNi189
S30400
00Cr19Ni11 03X18H11 304L 304S12 SUS304L Z2CN18.09 X2CrNi189
S30403
0Cr18Ni11Ti 08X18H10T 321 321S12 SUS321 Z6CNT18.10 X10CrNiTi189
S32100 321S20
0Cr13Al 405 405S17 SUS405 Z6CA13 X7CrAl13
S40500
1Cr17 12X17 430 430S15 SUS430 Z8C17 X8Cr17
S43000
1Cr13 12X13 410 410S21 SUS410 Z12C13 X10Cr13
S41000
2Cr13 20X13 420 420S37 SUS420J1 Z20C13 X20Cr13
S42000
3Cr13 30X13 420S45 SUS420J2
7Cr17 440A SUS440A
S44002
0Cr17Ni7Al 09X17H7Ю 631 SUS631 Z8CNA17.7 X7CrNiAl177
S17700
Heat resistant steel 2Cr23Ni13 20X23H12 309 309S24 SUH309 Z15CN24.13
S30900
2Cr25Ni21 20X25H20C2 310 310S24 SUH310 Z12CN25.20 CrNi2520
S31000
0Cr25Ni20 310S SUS310S
S31008
0Cr17Ni12Mo2 08X17H13M2T 316 316S16 SUS316 Z6CND17.12 X5CrNiMo1810
S31600
0Cr18Ni11Nb 08X18H12E 347 347S17 SUS347 Z6CNNb18.10 X10CrNiNb189
S34700
1Cr13Mo SUS410J1
1Cr17Ni2 14X17H2 431 431S29 SUS431 Z15CN16-02 X22CrNi17
S43100
0Cr17Ni7Al 09X17H7Ю 631 SUS631 Z8CNA17.7 X7CrNiAl177
S17700
Alloy steel production flow chart
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