The thickness tolerance of stainless steel plate

/v /od

We usually call the thickness of 4-25.0 mm stainless steel plate in the middle plate, the thickness of 25.0-100.0mm stainless steel thick plate, thickness of more than 100.0mm is extra thick plate.When looking for a suitable stainless steel plate, there are several different grades available based on the strength of the metal and its chemical composition. There is a high grade that is made from Cr-Ni alloys which are generally used in commercial applications such as Pressure vessels, boiler shells, bridges, automobiles, shipbuilding, construction and other industrial purposes.

It is important to note what type of use the stainless steel plate is going to have in any given industrial application. Some applications require a hardened, reinforced plate that is able to withstand hammer blows, abrasions and impact. Others may require a more brittle, softer material that is able to cope with bending and deformation. The other criteria that need to be observed is the degree of corrosion resistance and this will dictate what grade of stainless steel plate is best for the application. The conmmonly used grades are 304, 316L, 310S, and 904L stainless steel plate. Here is the allowable thickness tolerance of stainless steel plate from ASTM, JIS and GB specification.

 

JIS Stainless steel plate

Thickness Width
<1250 ≥1250<1600
≥0.30~<0.60 士0.05 士0.06
≥0.60~<0.80 士0.07 士0.09
≥0.80~<1.00 士0.09 士0.10
≥1.00~<1.25 士0.10 士0.12
≥1.25~<1.60 士0.12 士0.15
≥1.60~<2.00 士0.15 士0.17
≥2.00~<2.50 士0.17 士0.20
≥2.50~<3.15 士0.22 士0.25
≥3.15~<4.00 士0.25 士0.30
≥4.00~<5.00 士0.35 士0.40
≥5.00~<6.00 士0.40 士0.45
≥6.00~<7.00 士0.50 士0.50

 

ASTM Stainless steel plate

Thickness Allowable tolerance Width
上 下 ≤1000 ＞1000~≤1300
0.10 0.03 0.03
0.15 0.04 0.04
0.20 0.05 0.05
0.25 0.05 0.05
0.30 0.03 ——-
0.40 0.04 0.04
0.50 0.08 0.08
0.50 0.045 0.05
0.60 0.05 0.05
0.75 0.10 0.10
0.80 0.05 0.05
1.00 0.055 0.06
1.20 0.08 0.08
1.25 0.13 0.13
1.50 0.08 0.08
1.75 0.15 0.15
2.00 0.18 0.18
2.00 0.10 0.10
2.25 0.20 0.20
2.50 0.23 0.23
2.50 0.10 0.11
2.75 0.25 0.25
3.00 0.25 0.25
3.00 0.13 0.13
3.25 0.30 0.30
3.50 0.30 0.30
3.75 0.36 0.36
4.00 0.36 0.36
4.00 0.17 0.17
4.99 0.36 0.36
5.00 0.17 0.17
6.00 0.17 0.20
8.00 0.17 0.

 

GB Stainless Steel Plate

Thickness Allowable thickness tolerance
High precision(A) Standard precision(B)
>600~1000 >1000~1250 >600~1250
0.05~0.10 ——- ——- ——-
>0.10~0.15 ——- ——- ——-
>0.15~0.25 ——- ——- ——-
>0.25~0.45 士0.040 士0.040 士0.040
>0.45~0.65 士0.040 士0.040 士0.050
>0.65~0.90 士0.050 士0.050 士0.060
>0.90~1.20 士0.050 士0.060 士0.080
>1.20~1.50 士0.060 士0.070 士0.110
>1.50~1.80 士0.070 士0.080 士0.120
>1.50~2.00 士0.090 士0.100 士0.130
>2.00~2.30 士0.100 士0.110 士0.140
>2.30~2.50 士0.100 士0.110 士0.140
>2.50~3.10 士0.110 士0.120 士0.160
>3.10~4.00 士0.120 士0.130 士0.180

Is 318LN a type duplex stainless steel grades?

/v /od

318LN is Nitrogen-enhanced stainless steel commonly used to address corrosion failures in 300 series stainless steel. The structure of 318LN stainless steel is composed of Austenite surrounded by continuous Ferrite phases. 318LN contains about 40-50% Ferrite in the annealed state and can be considered duplex stainless steel. The duplex structure combines ferrite alloys (stress corrosion cracking resistance and high strength) with the superior qualities of Austenitic alloys (ease of manufacture and corrosion resistance). The 318LN is resistant to H2S uniform corrosion, sulfide stress cracking, hydrogen embrittability and pitting, and reducing media corrosion. It is commonly used to manufacture sulfur-resistant wellheads, valves, stems, and fasteners for use in mining environments where H2S partial pressures exceed 1MPa. However, the use of 318LN duplex stainless steel should be limited to less than 600°F because prolonged high temperatures can brittle the 318LN stainless steel.

 

The chemical composition of 318LN steel

Cr Ni Mo C N Mn Si P S
22.0-23.0 4.50-6.50 3.00-3.50 ≤0.030 0.14-0.20 ≤2.00 ≤1.00 ≤0.030 ≤0.020
Mechanické vlastnosti
Ys (Mpa) Ts (Mpa) Elongation (%) Hv
Normy ≥ 450 ≥ 620 ≥ 18
Physical property
Density (g/cm) Specific heat(J/g.C) Thermal conductivity

100C(W/m.)

 The coefficient of thermal expansion

20~100C (10/C)
7.8 0.45 19.0 13.7

 

Features of 318LNsteel

  • Excellent resistance to sulfide stress corrosion
  • Good resistance to chloride stress corrosion cracking, pitting and crevice corrosion
  • High strength,
  • Good weldability and workability

 

Applications of 318LNsteel

  • Chemical treatment containers, pipes and heat exchangers
  • Pulp mill digesters, bleach cleaners, chip presteam containers
  • Food processing equipment
  • Petrochemical pipelines and heat exchangers
  • Flue gas desulfurization equipment

 

318LN duplex stainless steel is an economical and effective solution for applications where 300 series stainless steel are susceptible to chloride stress corrosion cracking. When stainless steel is subjected to tensile stress, stress corrosion cracking will occur in contact with a solution containing chloride, and rising temperature will also increase the sensitivity of stainless steel to stress corrosion cracking. The combination of chromium, molybdenum, and nitrogen enhances the 318LN’s resistance to chloride pitting and crevice corrosion, which is critical for services such as marine environments, brackish water, bleaching operations, closed-loop water systems, and some food processing applications. In most environments, 318LN’s high chromium, molybdenum and nitrogen content provides superior corrosion resistance to ordinary stainless steels such as 316L and 317L.

Vysokopevnostní nerezová ocel používaná v leteckých aplikacích

/v /od

We usually call tensile strength higher than 800MPa, yield strength higher than 500MPa stainless steel is high strength stainless steel, yield strength higher than 1380MPa stainless steel is called ultra high strength stainless steel. The development of the aviation industry has proved that the improvement of aircraft and aero-engine performance largely depends on metal materials. Due to the high strength, high toughness, high stress corrosion cracking resistance and good impact resistance of steel, some key structural components of aircraft such as landing gear, girder, high stress joints, fasteners and other high strength stainless steel are still used.

High strength stainless steel mainly includes Martensite precipitation hardening stainless steel and semi – Austenite precipitation hardening stainless steel. The strength of martensite precipitation hardening stainless steel is achieved by martensite transformation and precipitation hardening treatment, the advantage is high strength, at the same time due to low carbon, high chromium, high molybdenum and/or high copper, its corrosion resistance is generally not less than 18Cr-8Ni austenitic stainless steel; Free cutting, good welding ability, do not need local annealing after welding, heat treatment process is relatively simple. The main disadvantage is that even in annealed state, its structure is still low carbon martensite, so it is difficult to conduct deep deformation cold working. The typical steel grade is 17-4PH and PH13-8Mo, used for the manufacture of high strength corrosion resistant bearing components, such as engine bearing parts, fasteners, etc. working at 400℃. PH13-8Mo is widely used in aeronautical bearing corrosion resistant medium temperature structural parts.

The semi-Austenite precipitation hardened stainless steel can be machined, coldly deformed and welded in Austenite state, and then the martensite transformation and precipitation hardening can be controlled by adjusting aging to obtain different strengths and toughness coordination. The steel has good corrosion resistance and thermal strength, especially stress corrosion resistance, and is especially suitable for the manufacture of parts used below 540℃. The disadvantage is that the heat treatment process is complex, the heat treatment temperature control requirements are very accurate (±5℃); The work hardening tendency of steel is large, and many intermediate annealing times are often needed for deep deformation cold working. Typical grades are 17-7PH, PH15-7Mo, etc. This kind of steel is mainly used in the aviation industry to work at 400℃ below the corrosion bearing structure, such as all kinds of pipes, pipe joints, springs, fasteners, etc.

 

Aircraft landing gear

The materials used for the construction of aircraft landing gear are 30CrMnSiNi2A, 4340, 300M, Aermet100 and other aircraft landing gear and fasteners with higher requirements are mostly made of precipitation hardened stainless steel, such as 17-4PH for THE landing gear of F-15 aircraft, 15-5pH for the landing gear of B-767 aircraft. PH13-8mo steel has the potential to replace 17-4PH, 15-5PH, 17-7PH, PH15-7Mo and other steels due to its better stress corrosion resistance than precipitation hardened stainless steel of the same grade.

The plane bearing

German FAG company developed the nitrogen-added martensite stainless steel Cronidur30 (0.31%C-0.38%N-15% Cr-L %Mo), which is produced by PESR process of electroslag remelting under high pressure nitrogen atmosphere. It is a high temperature stainless steel with high nitrogen completely hardened, which is more resistant to corrosion than SUS440. It is not suitable for high DN value (D: bearing inner diameter/mm, N: shaft revolution/arin) because of its characteristics of full hardening type, the same Cronidur30 can satisfy the residual compressive stress and fracture toughness value of DN4 million at the same time through high-frequency quenching. But the tempering temperature is lower than 15O℃, it can not withstand the rise in bearing temperature caused by thermal shock after engine shutdown.

Aircraft bearing structural components

High-strength stainless steel in aircraft bearing structure is mainly 15-5PH, 17-4PH, PH13-8Mo, etc., including hatch cover latch, high-strength bolt, spring and other parts. Civil aircraft use such high-strength stainless steel for wing spars, such as 15-5PH steel for Boeing 737-600 wing spars; Type A340-300 wing SPAR PH13-8Mo steel. Ph13-8Mo is used for parts requiring high strength and toughness, especially for transverse performance, such as fuselage frames. More recently, Custom465 has been tested due to increased toughness and stress corrosion resistance. Custom465 was developed by Carpenter on the basis of Custom450 and Custom455 for the manufacture of aircraft flap guides, slat guides, transmissions, engine mounts, etc. The steel is currently included in the MMPDS-02, AMS5936 and ASTM A564 technical specifications. HSL180 high strength stainless steel (0.21C-12.5Cr-1.0Ni-15.5Co-2.0Mo) is used to manufacture the aircraft structure, which has the same strength of 1800MPa as low alloy steel such as 4340 and the same corrosion resistance and toughness as precipitation hardened stainless steel such as SUS630.

 

Výhody nerezového kulového tvaru

/v /od

Armatury z nerezové oceli, zejména tee, klouby a redukční tvarovací kroužky, jsou stále častěji používány v technologii potrubí díky svým dobrým vlastnostem v oblasti tvarování, odolnosti proti korozi, vysoké teplotě a odolnosti proti vysokému tlaku, svařování a jiným vlastnostem. V porovnání s armaturami z uhlíkové oceli jsou armatury z nerezové oceli často používány v dopravě pitné vody, petrochemickém průmyslu a dalších potrubích s vysokými požadavky na prostředí. Aby bylo vše jasné pro ty, kteří o nich moc nevědí, tento článek vám poskytne informace o této řadě výrobků a jejich různých vlastnostech. Kromě toho se v něm také probereme o výhodách, které můžete očekávat z jejich používání. Do té doby, než si tento článek přečtete do konce, budete určitě mít dobrý přehled o tom, co tyto výrobky jsou a jak si je můžete zakoupit.

Specifikace ocelového kloubu 304

DN NPS Serie A Řada B 45° koleno 90° koleno Obrček 180°
DN NPS Serie A Řada B L.R L.R S.R. L.R S.R. L.R S.R.
15 1/2 21.3 18 16 38 – 76 – 48 –
20 3/4 26.9 25 19 38 – 76 – 51 –
25 1 33.7 32 22 38 25 76 51 56 41
32 1.1/4 42.4 38 25 48 32 95 64 70 52
40 1.1/2 48.3 45 29 57 38 114 76 83 62
50 2 60.3 57 35 76 51 152 102 106 81
65 2.1/2 76.1(73) 76 44 95 64 190 127 132 100
80 3 88.9 89 51 114 76 229 152 159 121
90 3.1/2 101.6 – 57 133 89 267 178 184 140

Tyto běžně používané třídy v potrubních spojích jsou 304Nerezové kolena typu 316 a 316l. Často se používají v průmyslu výroby a automobilového průmyslu, v farmaceutickém a potravinářském průmyslu. Ve skutečnosti není ničím výjimečným, že tyto výrobky lze nalézt v potravinářských závodech. Důvod jejich širokého využití je poměrně jednoduchý – poskytují účinnou oporu pracovním částem strojního zařízení, aniž by narušovali kvalitu práce. Jak již bylo zmíněno výše, používají speciálně navržený proces svařování s názvem „bending heat cure“, který zajišťuje, že kloub kolene je podepřen vysoce pevnými armaturami z nerezové oceli. To zase zajišťuje, že armatury lze kdykoli vyměnit.

Další významnou výhodou použití armatury z nerezové oceli je její odolnost proti korozi. Protože je nerezová ocel slitinová ocel s přídavkem Cr a Mo, má potenciál stát se nedílnou součástí mnoha průmyslových procesů, kde je vodivost zásadní. To znamená, že elektrický výpadek může ovlivnit fungování zařízení a nemusí to být jen otázka vypnutí napájení. Například při výpadku proudu v chemickém výrobním závodě musí záchranný personál do oblasti vstoupit sám, což by pro ně mohlo být velmi obtížné, pokud nejsou správně umístěny body rozvodu proudu.

 

WLD steel je 304 Dodavatel a výrobce nerezových ocelových kolen o úhlu 90°. Prvním krokem je jejich výroba s cílem zajistit nejvyšší kvalitu výkonu. To znamená, že jsou opatřeny nerezovými armaturními přípojkami správného průměru a délky pro daný účel, bez ohledu na velikost nebo tvar potrubí. Například může být potřeba namontovat trubky různých šířek, od dvou palcových až po čtyři palcové. Dobře navržený výrobek bude moci tyto požadavky splnit bez jakýchkoli problémů.