Basic Info.
Standard
ANSI, DIN, GOST, En1092-1
Ndividual Drawing
Welcome
Transport Package
Pallet/Wooden Case
Product Description
Austenitic Stainless Steel
Austenitic steels are the most popular grades of stainless steels because of their ductility, ease of working and good corrosion resistance and are very commonly used in manufacture of piping components. Austenitic steels are non-magnetic and non-hardenable by heat treatment, however they can be hardened by cold working. The most commonly used stainless steel grades are Type 304, Type 316 and Type 321.
Stainless steel grades with suffix L have low carbon content. The low carbon content provides good weldability and good corrosion resistance after welding, however they have lower strength than the grades with higher carbon content. The dual certified grades of stainless steel are commonly used in the industry such as SS 304/304L or SS 316/316L. For e.g. the SS 304/304L dual certified grade has lower carbon content similar to SS 304L grade but higher mechanical strength of SS 304 grade.
Type 304 grade contains approximately 18% Chromium and 8% Nickel.
Effect of carbon on corrosion resistance
The lower carbon variants (316L) were established as alternatives to the standards (316) carbon range grade to overcome the risk of intercrystalline corrosion (weld decay), which was identified as a problem in the early days of the application of these steels. This can result if the steel is held in a temperature range 450 to 850°C for periods of several minutes, depending on the temperature and subsequently exposed to aggressive corrosive environments. Corrosion then takes place next to grain boundaries.
If the carbon level is below 0.030% then this intercrystalline corrosion does not take place following exposure to these temperatures, especially for the sort of times normally experienced in the heat affected zone of welds in thick sections of steel.
Effect of carbon level on weldability
There is a view that the low carbon types are easier to weld than the standard carbon types.
There does not seem to be a clear reason for this and the differences are probably associated with the lower strength of the low carbon type. The low carbon type may be easier to shape and form, which in turn may also affect the levels of residual stress left the steel after is forming and fitting up for welding. This may result in the standard carbon types needing more force to hold them in position once fitted-up for welding, with more of a tendency to spring-back if not properly held in place.
The welding consumables for both types are based on a low carbon composition, to avoid intercrystalline corrosion risk in the solidified weld nugget or from the diffusion of carbon into the parent (surrounding) metal.
Dual-certification of low carbon composition steels
Commercially produced steels, using current steelmaking methods, are often produced as the low carbon type as a matter of course due to the improved control in modern steelmaking. Consequently finished steel products are often offered to the market dual certified to both grade designations as they can then be used for fabrications specifying either grade, within a particular standard.
Raw Material Specification
A/SA182 F304 / 304L Technical Data
Summary
304 is the most versatile and the most widely used of all stainless steels. Its chemical composition, mechanical properties, weldability and corrosion/oxidation resistance provide the best all-round performance stainless steel at relatively low cost. It also has excellent low temperature properties and responds well to hardening by cold working. If intergranular corrosion in the heat affected zone may occur, it is suggested that 304L be used.
Typical Applications
304 is used in all industrial, commercial and domestic fields because of its good corrosion and heat resisting properties. Some applications include:
Tanks and containers for a large variety of liquids and solids.
Process equipment in the mining, chemical, cryogenic, food, dairy and pharmaceutical industries.
Chemical Composition (ASTM/ASME A/SA182)
A/SA182 | C | Mn | P | S | Si | Cr | Ni |
304 304L | 0.08 max 0.03 max | 2.0 max | 0.045 max | 0.030 max | 1.0 max | 18.0 to 20.0 | 8.0 to 11 8.0 - 12.0 |
Typical Properties in the Annealed Condition
The properties quoted in this publication are typical of mill production and unless indicated should not be regarded as guaranteed minimum values for specification purposes. 1. Mechanical Properties at Room Temperature
| 304 | 304L |
Typical | Minimum | Typical | Minimum |
Tensile Strength, MPa | 600 | 515 | 590 | 485 |
Proof Strength, (Offset 0.2 %), MPa | 310 | 205 | 310 | 170 |
Elongation (Percent in 50mm) | 60 | 40 | 60 | 40 |
Hardness (Brinell) | 170 | - | 170 | - |
Endurance (fatigue) limit, MPa | 240 | - | 240 | - |
2. Properties at elevated temperatures
All these values refer to 304 only.
304L values are not given because its strength decreases markedly above 425oC.
Time Elevated Temperature Tensile Strength Temperature, oC | 600 | 700 | 800 | 900 | 1000 |
Tensile Strength, MPa | 380 | 270 | 170 | 90 | 50 |
Creep data Stress for a creep rate of 1% in 10 000 h.Temperature, oC | 550 | 600 | 650 | 700 | 800 |
Stress, MPa | 120 | 80 | 50 | 30 | 10 |
Maximum Recommended Service Temperature
(Oxidising Conditions)Continuous Service 925oC
Intermittent Service 850oC3. Properties at Sub-Zero Temperatures
( 304 / 304L ) Temperature | oC | -78 | -161 | -196 |
Tensile Strength | MPa | 1100/950 | 1450/1200 | 1600/1350 |
Proof Stress (Offset 0.2%) | MPa | 300/180 | 380/220 | 400/220 |
Impact Strength (Charpy V-Notch) | J | 180/175 | 160/160 | 155/150 |
4. Corrosion Resistance Aqueous
As a rough guide the following examples are given for certain pure acid-water mixtures-Temperature oC | 20 | 80 |
Concentration, % by mass | 10 20 40 60 80 100 | 10 20 40 60 80 100 |
Sulphuric Acid | 2 2 2 2 1 0 | 2 2 2 2 2 2 |
Nitric Acid | 0 0 0 0 2 0 | 0 0 0 0 1 2 |
Phosphoric Acid | 0 0 0 0 0 2 | 0 0 0 0 1 2 |
Formic Acid | 0 0 0 0 0 0 | 0 1 2 2 1 0 |
Key: 0 = resistant - corrosion rate less than 100 mm/year
1 = partly resistant - corrosion rate 100m to 1000 mm/year
2 = non resistant - corrosion rate more than 1000 mm/year
4.2 Atmospheric The performance of 304 compared with other metals in various environments is shown in the following table. The corrosion rates are based on a 10 year exposure.
Environment | Corrosion Rate (mm/year) |
SX 304 | Aluminium-3S | Mild Steel |
Rural | 0.0025 | 0.025 | 5.8 |
Marine | 0.0076 | 0.432 | 34.0 |
Marine Industrial | 0.0076 | 0.686 | 46.2 |
Thermal Processing
1. Annealing. Heat from 1010oC to 1120oC and cool rapidly in air or water. The best corrosion resistance is obtained when the final annealing is above 1070oC and cooling is rapid.
2. Stress relieving. 304L can be stress relieved at 450-600oC for one hour with little danger of sensitisation. A lower stress relieving temperature of 400oC maximum must be used.
3. Hot working
Initial forging and pressing: 1150 to 1260oC
Finishing temperature: 900 to 925oC
All hotworking operations should be followed by annealing.
Note: Soaking times to ensure uniformity of temperature are longer for stainless steels than for carbon steels - approximately 12 times.
Cold Working
304 / 304L being extremely tough and ductile, are readily fabricated by old working. Typical operations include bending, forming, deep drawing and upsetting
Shipped Flange Photos
Production Range
DN15-DN3000
Maximum weight 6tons
25,000tons production annual year
Manufacturing Standard
ANSI B16.5,ANSI B16.47 Series A&B,ANSI B16.48,ANSI B16.36
API 605,API 16D,API 17D
BS4504,BS3293
DIN
AS
EN1092-1
GOST
EEMUA145
Inspection Certificate
EN10204-3.1
EN10204-3.2 byTUV,BV,Lloyds,GL,DNV,SGS,ABS,RINA,Moody or other third parties
Address:
Building 9, No. 1558, Kangqiao Rd., Pudong, Shanghai, China
Business Type:
Manufacturer/Factory, Trading Company
Business Range:
Chemicals, Construction & Decoration, Industrial Equipment & Components, Manufacturing & Processing Machinery, Metallurgy, Mineral & Energy, Tools & Hardware
Management System Certification:
ISO 9001, ISO 14001, ASME
Company Introduction:
Dingxiang CHN Flange Forging Co., Ltd. is located in the State Dingxiang named"hometown of forging", founded in 2006 invested by TianYuan(HK) International Limited be specialized in manufacturing various kinds of high quality flange and other forging.
Being a designer and manufacturer of flange and forgings in the industry. We provide both standard and customized designs in a large range of different pipeline system. Our main products include Welding Neck, Slip-on, SocketWelding, Threaded, Binld according to ANSI, DIN, JIS, EN, made of ASTM A105, A350, A694, A182, ect. Our engineers are able to design the right products to fit your application and the best solution for your requirements. The products have been wildely used in the industries of petroleum, chemical, foodstuff, metallurgy, construction, electric power and so on.
We have a 4, 000tons Hydraulic Machine and 6300 Ring Rolling Machine operating flange&ring production, the maximum outside diameter is up to 6000mm, maximum gross weight up to 6tons. Our annual production capacity of Flange is 25000tons;
We do a whole set of chemical and mechanical performance test, metallurgical structure, hardness test, NDE test, salt-fog test, film thickness test, roughness test, and the lowest temperature of impact test can be -196 degree C.
We treat Quality, Customer, Market, Upgrade as the most important.