Allowable deviation of thickness of stainless steel plate and steel strip for pressure equipment(1)

Allowable deviation of thickness of stainless steel hot-rolled thick steel plate for pressure equipment (GB 24511 – 2009)

Nominal thickness① Nominal width
<=1000 >1000~1500 >1500~2500 >2500
Ordinary precision Higher precision Ordinary precision Higher precision Ordinary precision Higher precision
Negative thickness deviation is -0.30
5.0~8.0 0.38 0.35 0.40 0.36 0.50 0.45 0.80
>8.0~15.0 0.45 0.42 0.48 0.44 0.60 0.55
>15.0~25.0 0.50 0.45 0.53 0.48 0.65 0.60 1.00
>25.0~40.0 0.65 0.60 0.70 0.65 0.85 0.80
>40.0~60.0 0.90 0.85 0.95 0.90 1.10 1.05 1.50
>60.0~80.0 0.90 0.85 0.95 0.90 1.40 1.35

①The thickness tolerance of the nominal thickness >80~100mm is negotiated by both the supplier and the buyer.

Mechanical properties of heat-treated austenitic-ferritic stainless steel sheets and strips for pressure equipment at room temperature (GB 24511 – 2009)

Brand Maximum thickness of each type of product Specified plastic elongation strength Rp0.2/MPa Tensile strength Rm/MPa Elongation after break A(%) Hardness
HBW HRC

>=

<=

022Cr19Ni5Mo3Si2N C 8 440 630 25 290 31
H 14
P 80
022Cr22Ni5Mo3N C 8 450 620 25 293 31
H 14
P 80
022Cr23Ni5Mo3N C 8 450 620 25 293 31
H 14
P 80

Stainless steel cold-rolled steel sheet and steel strip

Wide steel strip and coiled steel sheet, slitting wide steel strip and coiled steel strip Ⅰ(GB/T 3280-2015)(unit:mm)

Nominal width Sickle bend on any length of 1000mm Nominal width Sickle bend on any length of 1000mm
10~<40 <=2.5 125~<600 <=1.5
40~<125 <=2.0 600~<2100 <=1.0

Narrow steel strip and coil cutting steel strip II(GB/T 3280-2015)(unit:mm)

Nominal width Sickle bend on any length of 1000mm Nominal width Sickle bend on any length of 1000mm
PC.A PC.B PC.A PC.B
10~<25 <=4.0 <=1.5 40~<125 <=2.0 <=1.0
25~<40 <=3.0 <=1.25 125~<600 <=1.5 <=0.75

Flatness of stainless steel cold-rolled steel plate and strip

              The degree of flatness of rolled steel plate and rolled steel strip(GB/T 3280-2015)(unit: mm)

Nominal length Flatness error
PF.A PF.B
<=3000 <=10 <=7
>3000 <=12 <=8

①Not suitable for cold hardened steel plate and 2D products

                                                             Flatness of II rolled steel strip①(GB/T 3280—2015)

Nominal length Flatness error
PF.A PF.B
Any length <=6 <=4

①Not suitable for cold work hardened steel plates and 2D products. The flatness error of the unrolled roll-cut strip II below 0.1 mm in thickness is negotiated between the supplier and the buyer.

      Flatness of rolled steel plate under different cold hardening conditions①(GB/T 3208—2015) (unit: mm)

Nominal width Thickness Flatness error
H1/4 H1/2 H3/4、H、H2
600~<900 0.10~0.40 <=19 <=23 According to the agreement between supply and demand
>0.40~0.80 <=16 <=23
>0.80 <=13 <=19
900~<2100 <=0.40 <=26 <=29 According to the agreement between supply and demand
>0.40~0.80 <=19 <=29
>0.80 <=16 <=26

①Only applicable to austenitic and austenitic-ferritic stainless steel plates (except soft and deep drawn plates).

Width tolerance of narrow cut strips and coil cut strips II (GB/T 3280-2015)

(unit:mm)

Nominal thickness

Nominal width

≤40

>40~125

>125~250

>250~600

PW.A

PW.B

PW.A

PW.B

PW.A

PW.B

PW.A

PW.B

0.05-~0.25

+0.17

0

+0.13

0

+0.20

0

+0.15

0

+0.25

0

+0.20

0

+0.50

0

+0.50

0

0.25-~0.50

+0.20

0

+0.15

0

+0.25

0

+0.20

0

+0.30

0

+0.22

0

+0.60

0

+0.50

0

0.50-~1.00

+0.25

0

+0.20

0

+0.30

0

+0.22

0

+0.40

0

+0.25

0

+0.70

0

+0.60

0

1.00-~1.50

+0.30

0

+0.22

0

+0.35

0

+0.25

0

+0.50

0

+0.30

0

+0.90

0

+0.70

0

1.50-~2.50

+0.35

0

+0.25

0

+0.40

0

+0.30

0

+0.60

0

+0.40

0

+1.0

0

+0.08

0

2.50-~3.00

+0.40

0

+0.30

0

+0.50

0

+0.40

0

+0.65

0

+0.50

0

+1.2

0

+1.0

0

After consultation between the supplier and the buyer, the width deviation can be positive or negative, but the tolerance value should not exceed the range of the table.

Width tolerances for width and width of cut wide steel strip, coil cut steel plate, slit strip and coil cut strip I (GB/T 3280-2015)

Unit :mm

Nominal thickness

Nominal width

≤125

>125~250

>125~250

>125~250

PW.A

PW.B

PW.A PW.B PW.A PW.B PW.A

PW.B

<1.00

+0.5

0

+0.3

0

+0.5

0

+0.3

0

+0.7

0

+0.6

0

+1.5

0

+2.0

0

1.00-~1.50

+0.7

0

+0.4

0

+0.7

0

+0.5

0

+1.0

0

+0.7

0

+1.5

0

+2.0

0

1.50-~2.50

+1.0

0

+0.6

0

+1.0

0

+0.7

0

+1.2

0

+0.9

0

+2.0

0

+2.5

0

2.50-~3.50

+1.2

0

+0.8

0

+1.2

0

+0.9

0

+1.5

0

+1.0

0

+3.0

0

+3.0

0

3.50-~8.00

+2.0

0

 _

+2.0

0

 _

+2.0

0

 _

+4.0

0

+4.0

0

With the consent of the demander, the product can be delivered less than the nominal width, but it should not exceed the range of the listed tolerances.

With the consent of the demander, the width deviation can be increased to 5mm for slitting products requiring secondary trimming.

Thickness tolerance of narrow strip and coil cut strip II (GB/T 3280-2015)

Unit (mm)

Nominal thickness PT.A PT.B
Nominal thickness Nominal thickness
<125 125~<250 250~<600 <125 125~<250 250~<600
0.05~<0.10 ±0.10t ±0.12t ±0.15t ±0.06t ±0.10t ±0.10t
0.10~<0.20 ±0.010 ±0.015 ±0.020 ±0.008 ±0.012 ±0.015
0.20~<0.30 ±0.015 ±0.020 ±0.025 ±0.012 ±0.015 ±0.020
0.30~<0.40 ±0.020 ±0.025 ±0.030 ±0.015 ±0.020 ±0.025
0.40~<0.60 ±0.025 ±0.030 ±0.035 ±0.020 ±0.025 ±0.030
0.60~<1.00 ±0.030 ±0.035 ±0.040 ±0.025 ±0.030 ±0.035
1.00~<1.50 ±0.035 ±0.040 ±0.045 ±0.030 ±0.035 ±0.040
1.50~<2.00 ±0.040 ±0.050 ±0.060 ±0.035 ±0.040 ±0.050
2.00~<2.50 ±0.050 ±0.060 ±0.070 ±0.040 ±0.050 ±0.060
2.50~<3.00 ±0.060 ±0.070 ±0.080 ±0.050 ±0.060 ±0.070

Note:

1. The supplier and the buyer negotiate and confirm that the deviation value can be all positive deviation/negative deviation or positive and negative deviation asymmetric distribution, but the tolerance value should be within the range of the list.

2. When the thickness is less than 0.05mm, it is negotiated between the supplier and the buyer.

3. The height of the burr on the edge of the strip should be less than or equal to the nominal thickness of the product × 10%

4. t is the nominal thickness

Width tolerances for wide strips and coil cut steel plates, slits for wide strips, and coil cut strips (GB/T 3280-2015)

(unit:mm)

Nominal thickness

PT.A

PT.B

Nominal width

Nominal width

<1250 1250 ~ 2100 600 ~ <1000 1000 ~ <1250

1250 ~ 2100

0.10 ~<0.25

±0.03 _ _ _ _

0.25~<0.30

±0.04 _ ±0.038 ±0.038 _

0.30~<0.60

±0.05 ±0.08 ±0.040 ±0.040

±0.05

0.60~<0.80

±0.07 ±0.09 ±0.05 ±0.05

±0.06

0.80~<1.00

±0.09 ±0.10 ±0.05 ±0.06

±0.07

1.00~<1.25

±0.10 ±0.12 ±0.06 ±0.07

±0.08

1.25~<1.60

±0.12 ±0.15 ±0.07 ±0.08

±0.10

1.60~<2.00

±0.15 ±0.17 ±0.09 ±0.10

±0.12

2.00~<2.50

±0.17 ±0.20 ±0.10 ±0.11

±0.13

2.50~<3.15

±0.22 ±0.25 ±0.11 ±0.12

±0.14

3.15~<4.00

±0.25 ±0.30 ±0.12 ±0.13

±0.16

4.00~<5.00

±0.35 ±0.40 _ _

_

5.00~<6.50

±0.40

±0.45

_

_

_

6.50~<8.00 ±0.50 ±0.50 _ _

_

Mechanical properties of precipitation hardened stainless steel cold-rolled steel plates and strips treated with solution(GB/T 3280——2015)

Unified digital code Grade Steel thickness/mm Specified plastic elongation strength Rp0.2/MPa Tensile strength Rm/MPa Elongation after fractureA①(%)>= Hardness
HBW HRC
<= <=
S51380 04Cr13Ni8Mo2Al 0.10~<8.0 __ __ __ 38 363
S51290 022Cr12Ni9Cu2NbTi 0.30~<8.0 1105 1205 3 36 331
S51770 07Cr17Ni7Al 0.10~<0.30 450 1035 __ __ __
0.30~8.0 380 1035 20 92② __
S51570 07Cr15Ni7Mo2Al 0.10~<8.0 450 1035 25 100② __
S51750 09Cr17Ni5Mo3N 0.10~<0.30 585 1380 8 30 __
0.30~8.0 585 1380 12 30 __
S51778 06Cr17Ni7AlTi 0.10~<1.50 515 825 4 32 __
1.50~8.0 515 825 5 32 __

① Use A50mm sample when thickness is less than 3mm

② HRB hardness value

Annealed Martensitic Stainless Steel Cold Rolled Steel Sheets and Strips Mechanical Properties(GB/T3280-2015)

Unified digital code

Grade

Specified plastic elongation strength

Rp0.2/MPa

Tensile strength

Rm/MPa

Elongation after fractureA①(%)

180 degree bending performance bending head diameter D

Hardness

HBW

HRW HV
>=

<=

S40310

12Cr12 205 485 20 D=2a 217 96 210

S41008

06Cr13 205 415 22 D=2a 183 89 200

S41010

12Cr13 205 450 20 D=2a 217 96 210
S41595 04Cr13Ni5Mo 620 795 15  — 302 32②

308

S42020

20Cr13 225 520 18 223 97

234

S42030

30Cr13 225 540 18 235 99

247

S42040

40Cr13 225 590 15

S43120

17Cr16Ni2② 690 880-1080 12 262-326
1050 1350 10 388

S44070

68Cr17 245 590 15 255 25③

269

S46050 50Cr15MoV ≤850 12 280 100

280

Note: ‘a’  is the bending specimen thickness
①Use A50mm sample when the thickness is less than 3mm

②The table lists the mechanical properties after quenching and tempering

③ HRC hardness value

 

Mechanical properties of annealed ferritic stainless steel cold-rolled steel plates and strips

Unified digital code

Grade

Specified plastic elongation strengthRp0.2/MPa

Tensile strengthRm/MPa

Elongation after fractureA①(100%)

180 degree bending performance bending head diameter D

Hardness

HBW

HRW

HV

>=

<=

S11163 022Cr11Ti 170 380 20 D=2a 179 88 200
S11173 022Cr11NbTi 170 380 20 D=2a 179 88 200
S11203 022Cr12 195 360 22 D=2a 183 88 200
S11213 022Cr12Ni 280 450 18  — 180 88 200
S11348 06Cr13Al 170 415 20 D=2a 179 88 200
S11510 10Cr15 205 450 22 D=2a 183 89 200
S11573 022Cr15NbTi 205 450 22 D=2a 183 89 200
S11710 10Cr17 205 420 22 D=2a 183 89 200
S11763 022Cr17Ti 175 360 22 D=2a 183 88 200
S11790 10Cr17Mo 240 450 22 D=2a 183 89 200
S11862 019Cr18MoTi 245 410 20 D=2a 217 96 230
S11863 022Cr18Ti 205 415 22 D=2a 183 89 200
S11873 022Cr18Nb 250 430 18  — 180 88 200
S11882 019Cr18CuNb 205 390 22 D=2a 192 90 200
S11972 019Cr19Mo2NbTi 275 415 20 D=2a 217 96 230
S11973 022Cr18NbTi 205 415 22 D=2a 183 89 200
S12182 019Cr21CuTi 205 390 22 D=2a 192 90 200
S12361 019Cr23Mo2Ti 245 410 20 D=2a 217 96 230
S12362 019Cr23MoTi 245 410 20 D=2a 217 96 230
S12763 022Cr27Ni2Mo4NbTi 450 585 18 D=2a 241 100 242
S12791 008Cr27Mo 275 450 22 D=2a 187 90 200
S12963 022Cr29Mo4NbTi 415 550 18 D=2a 255 25② 257
S13091 008Cr30Mo2 295 450 22 D=2a 207 95 220

Note: ‘a’  is the bending specimen thickness
1 Use A50mm sample when the thickness is less than 3mm
2 HRC hardness value

Mechanical properties of cold-rolled steel plates and strips 3

Mechanical properties of solution treated austenitic-ferritic stainless steel cold rolled steel plates and strips(GB/T 3280-2015)

Unified digital code

Grade Specified plastic elongation strengthRp0.2/MPa Tensile strengthRm/MPa Elongation after fractureA①(100%) Hardness

HBW

HRC

>=

<=

S21860 14Cr18Ni11Si4AlTi __ 715 25 __

__

S21953

022Cr19Ni5Mo3Si2N 440 630 25 290 31
S22053 022Cr23Ni5Mo3N 450 655 25 293

31

S22152

022Cr21Mn5Ni2N 450 620 25 __ 25
S22153 022Cr21Ni3Mo2N 450 655 25 293

31

S22160

12Cr21Ni5Ti __ 635 20 __ __
S22193 022Cr21Mn3Ni3Mo2N 450 620 25 293

31

S22253

022Cr22Mn3Ni2MoN 450 655 30 293 31
S22293 022Cr22Ni5Mo3N 450 620 25 293

31

S22294

03Cr22Mn5Ni2MoCuN 450 650 30 290 __

S22353

022Cr23Ni2N 450 650 30 290 __
S22493 022Cr24Ni4Mn3Mo2CuN 540 740 25 290

__

S22553 022Cr25Ni6Mo3N 450 640 25 295

31

S23043

022Cr23Ni4MoCuN 400 600 25 290 31
S25073 022Cr25Ni7Mo4N 550 795 15 310

32

S25554

03Cr25Ni6Mo3Cu2N 550 760 15 302

32

S27603 022Cr25Ni7Mo4WCuN 550 750 25 270

__

①Use A50mm sample when thickness is less than 3mm

Mechanical properties of stainless steel cold rolled steel plates and strips in the HI/2 state (GB/T 3280-2015)

Unified digital code

Grade

Specified plastic elongation strength Rp0.2/Mpa

Tensile strength Rm/MPa

Elongation after fractureA①(%)

Thickness <0.4mm

Thickness 0.4~<0.8mm

Thickness

>=0.8mm

S30103

022Cr17Ni7

690

930 20 20

20

S30110

12Cr17Ni7

760

1035 15 18

18

S30153

022Cr17Ni7N

690 930 20 20

20

S30210

12Cr18Ni9

760

1035 9 10

10

S30403

022Cr19Ni10

760

1035 5 6

6

S30408

06Cr19Ni10

760

1035 6 7

7

S30453

022Cr19Ni10N

760

1035 6 7

7

S30458

06Cr19Ni10N

760

1035 6 8

8

S30603

022Cr17Ni12Mo2

760

1035 5 6

6

S31608

06Cr17Ni12Mo2

760

1035 6 7

7

S31658

06Cr17Ni12Mo2N

760

1035 6 8

8

Mechanical properties of stainless steel cold rolled steel plates and strips in the HI/4 state (GB/T 3280-2015)

Unified digital code Grade Specified plastic elongation strength Rp0.2/MPa Tensile strength Rm/MPa Elongation after fractureA①(%)
Thickness <0.4mm Thickness 0.4~<0.8mm Thickness  >=0.8mm

>=

S30103 022Cr17Ni7 515 825 25 25 25
S30110 12Cr17Ni7 515 860 25 25 25
S30153 022Cr17Ni7N 515 825 25 25 25
S30210 12Cr18Ni9 515 860 10 10 12
S30403 022Cr19Ni10 515 860 8 8 10
S30408 06Cr19Ni10 515 860 10 10 12
S30453 022Cr19Ni10N 515 860 10 10 12
S30458 06Cr19Ni10N 515 860 12 12 12
S31603 022Cr17Ni12Mo2 515 860 8 8 8
S31608 06Cr17Ni12Mo2 515 860 10 10 10
S31658 06Cr17Ni12Mo2N 515 860 12 12 12

①Use A50mm sample when thickness is less than 3mm.

Stainless steel definition, types and terms

First, the definition of stainless steel
A high alloy steel that resists corrosion in air or in chemically aggressive media. Stainless steel is aesthetically pleasing the surface and corrosion resistance are good. It is not necessary to perform surface treatment such as plating, but to exert the inherent surface properties of stainless steel.A type of steel used in many ways, often called stainless steel. Representative performance of 13 chrome steel, 18-chrome nickel steel, etc.High alloy steel.From the perspective of metallographic analysis, because the stainless steel contains chromium and forms a thin chromium film on the surface, this film is separated from the steel.Internally invaded oxygen plays a role in corrosion resistance.In order to maintain the inherent corrosion resistance of stainless steel, steel must contain more than 12% chromium.

Second, stainless steel types:
Stainless steel can be roughly classified according to its use, chemical composition and metallographic structure.The austenite type steel consists of 18% chromium-8% nickel, and the amount of each element added varies.Made various types of steel.
Classification by chemical composition:
1. CR Series: Ferritic Series, Martensitic Series
2. CR-NI Series: Austenitic Series, Abnormal Series,Precipitation Hardening Series.
Metallographic classification:
1. Austenitic stainless steel
2. Ferritic stainless steel
3. Martensitic stainless steel
4. Duplex stainless steel
5. Precipitation hardening stainless steel

Third, stainless steel professional terms
1. Austenitic stainless steel: Austenitic stainless steel at room temperature. Steel contains about 18% Cr, Ni 8%~10%,When C is about 0.1%, it has a stable austenite structure. Austenitic chromium-nickel stainless steel includes the famous 18Cr-8Ni steel and Based on this, a high
Cr-Ni series is developed by increasing the content of Cr and Ni and adding Mo, Cu, Si, Nb,Ti and other elements steel. Austenitic stainless steel is non-magnetic and has high toughness and plasticity, but its strength is low and it is impossible to make it through phase change.Strengthening can only be enhanced by cold working. Such as adding S, Ca, Se, Te and other elements, it has good ea Tearability. In addition to corrosion of oxidation-resistant acid media, such steels contain Mo, Cu, and other elements that are resistant to sulfuric acid and phosphoric acid.And formic acid, acetic acid, urea and other corrosion. If the carbon content in this type of steel is less than 0.03% or contains Ti, Ni,Improve its resistance to intergranular corrosion. High-silicon austenitic stainless steel concentrated nitric acid may have good corrosion resistance. Oxygen Body stainless steel has a comprehensive and good overall performance and has been widely used in various industries.
2. Ferritic stainless steel: Stainless steel with ferrite structure in use. Chrome content is 11%~30%, with a body-centered cubic crystal structure. This type of steel is generally nickel-free and sometimes contains small amounts of Mo, Ti, and Nb.This type of steel has many advantages such as high thermal conductivity, small expansion coefficient, good oxidation resistance, excellent resistance to stress corrosion, etc.In the manufacture of resistance to atmospheric, water vapor, water and oxidizing acid corrosion parts. This type of steel has poor plasticity and post-weld plasticity.The corrosion resistance is significantly reduced and other shortcomings, thus limiting its application. Application of outside refining technology (AOD or VOD).It can make carbon, nitrogen and other gap elements greatly reduced, so that this kind of steel is widely used.
3. Austenitic-ferritic duplex stainless steel: Austenitic and ferritic stainless steels are approximately one-half of each.In the case where the C content is low, the Cr content is 18% to 28%, and the Ni content is 3% to 10%. Some steels also contain Mo, Cu, Si, Nb, Ti, N and other alloying elements. This type of steel combines the characteristics of austenitic and ferritic stainless steels compared to ferrite., Plasticity, toughness, no room temperature brittleness, resistance to intergranular corrosion and welding performance are significantly improved, while maintaining Holds ferritic stainless steel 475 °C brittleness and high thermal conductivity, with features such as superplasticity. Austenite stainless .Compared with steel, high strength and resistance to intergranular corrosion and chloride stress corrosion resistance are significantly improved. Duplex stainless steel has excellent The resistance to pitting corrosion is also a kind of nickel-nickel stainless steel.
4. Martensitic stainless steel: Stainless steel that can adjust its mechanical properties through heat treatment, in layman’s terms, is a Hardenable stainless steel. Typical grades are Cr13 type, such as 2Cr13, 3Cr13, 4Cr13 and so on. After the fire hardnessHigh, different tempering temperatures with different toughness combinations, mainly for steam turbine blades, cutlery, surgical instruments Mechanical. According to the difference in chemical composition, martensitic stainless steel can be divided into martensitic chromium steel and martensitic chromium nickel steel. root According to different organization and strengthening mechanisms, it can be divided into martensitic stainless steel, martensite  maraging stainless steel.

Stainless steel material knowledge

1. What is stainless steel?

Stainless steel is based on ordinary carbon steel, adding a group of steel with a chromium (wCr) mass fraction of more than 12% alloy element, which maintains metallic luster under the effect of air, that is, it has no rust. This is due to the fact that the presence of a certain amount of chromium alloying elements in such steels enables the formation of a solid oxide film (passivation film) on the steel surface that is insoluble in certain media, so that the metal is isolated from the external substances without chemical effect. In addition to containing more chromium (Cr), some of these steels also match with other alloying elements, such as nickel (Ni), which are very good in air, water, and steam. Chemical stability, but also enough stability in many kinds of acid, alkali, salt aqueous solution, even in the high temperature or low temperature environment, it can still maintain its advantages of corrosion resistance.

2. There are several stainless steel classification methods?

According to the main chemical composition of chromium 316 stainless steel sheet, chromium nickel stainless steel and chromium manganese nitrogen stainless steel, etc.; can also be divided into acid-resistant stainless steel and heat-resistant stainless steel, etc.; usually classified by metallographic organization. Metallographic structure is divided into: ferritic (F) stainless steel, martensitic (M) stainless steel, austenitic – ferrite (A-F) duplex stainless steel, austenite – martensite ( A-M) duplex stainless steel and precipitation hardening (PH) stainless steel.

(1) Ferritic stainless steel F Ferrite has magnetic properties. Its internal microstructure is ferrite, and its chromium content is in the range of 11.5% to 32.0%. However, the carbon content is extremely low at <0.2% and cannot be quenched. With the increase of chromium content, the acid resistance is also improved. After adding molybdenum (Mo), the acid corrosion resistance and stress corrosion resistance can be improved.

(2) Martensitic stainless steel M The microstructure is martensite, and martensitic stainless steel is also magnetic. The mass fraction of chromium in such steel is 11.5%-18.0% but the mass fraction of carbon is up to 0.6%. Increased carbon content increases the strength and hardness of the steel. The small amount of nickel added to this type of steel promotes the formation of martensite while increasing its corrosion resistance. This type of steel has a certain degree of corrosion resistance, good thermal stability, and thermal strength and can be used as a heat-resistant steel that operates at temperatures below 700°C for long periods of time. It is widely used to make parts that require higher toughness and impact toughness, such as turbine blades, internal combustion engine exhaust valves, and medical devices.

(3) Austenitic stainless steel F. Its microstructure is austenite. It is formed by adding appropriate nickel (nickel mass fraction 8%-25%) in high chromium stainless steel (17-26%). With austenitic stainless steel, heat treatment is not used to refine the grain, nor can it be quenched to increase its hardness. This type of steel has a high degree of cold work hardening and is usually non-magnetic. After cold working, a small amount of ferrite or martensite can be precipitated in the steel, and a small amount of magnetism may appear. The austenitic steel sheet has the best overall performance. It has both sufficient strength, excellent plasticity, and low hardness. This is one of the reasons why they are widely used. Austenitic 304L Stainless Steel Bar are similar to most other metal materials. Their tensile strength, yield strength, and hardness increase with decreasing temperature; plasticity decreases with decreasing temperature. Its tensile strength increases rapidly in the temperature range of 15 to 800, and changes slowly when the temperature decreases further, while the increase in yield strength is more uniform. More importantly, as the temperature decreases, its impact toughness decreases slowly, and there is no brittle transition temperature.

(4) Special materials have been developed for the application of other special materials. For example: said austenitic-ferritic double steel, its microstructure is austenite plus ferrite. It contains 18-25% chromium, 4-7% nickel, and 4% molybdenum. Nickel, nickel-copper, nickel-chromium, and other nickel-chromium-based special stainless steels also fall into this category. This special material has special properties, such as ronifer, Nikrofer, AIIoy, ferrotherm, HasteIIoy, IncoIoy, InconeI, MoneI. These materials also have a material number and their chemical composition.

Stainless steel tableware cleaning and maintenance

Stainless steel is made from iron-chromium alloys that incorporate other trace elements. Due to its good metal properties and corrosion resistance compared to other metals, the finished vessel is beautiful and durable. Therefore, more and more are used to make cutlery and gradually enter the majority of families.

Regardless of how many times the manufacturer has magnified the advantages of stainless steel cutlery, its own safety risks are undeniable. The chief physician of Occupational Disease Hospital pointed out that although stainless steel is more resistant to corrosion than other metals, the use of trace metals by  316L Stainless Steel Bar  is inappropriate. Elements will also slowly accumulate in the human body, reaching a certain amount will endanger human health. She said that the nickel in stainless steel is a carcinogen, if too much intake will be harmful to the body. However, experts also stated that in fact, if tableware is not corroded and deteriorated, the use of normal life will have minimal impact on the human body.

Stainless steel tableware cleaning and maintenance

First, do not use alkaline or strong oxidizing chemicals such as baking soda, bleach, sodium hypochlorite, etc. for washing. Because these substances are all strong electrolytes, they react electrochemically with stainless steel to make dishes rust.

Second, before use, a thin layer of vegetable oil can be applied to the surface of the dishes, and then dried on fire. This is equal to the surface of the utensils put on a layer of yellowish oil film “clothes”. In this way, it is easy to use and can increase the service life.

Third, stainless steel cutlery is lower in thermal conductivity than iron and aluminum products, and the heat transfer time is slow. Burning will cause aging and shedding of the chrome plating on the surface of cookware. Therefore, do not avoid burning.

Fourth, salt, soy sauce, vinegar, vegetable soup, etc. cannot be preserved for a long time. Because these foods contain many electrolytes, if they are kept for a long time, the stainless steel will also react with these electrolytes like other metals. Harmful metal elements are dissolved out. Not only damage to the cutlery itself, but also harm the health of the human body.

Fifth, after the use of  17-7 Stainless Steel Aerospace Tubing cutlery, immediately wash with warm water, so as not to oil, soy sauce, vinegar, tomato juice and other substances and utensils surface effect, resulting in the stainless steel surface pale color, even dents.

Sixth, if there is a scale made of hard water, wipe the stain on the stainless steel utensils with a vinegar wipe or a paste of water and water, and then wash with hot soapy water.