2205 duplex stainless steel bolts, screws, nuts and flat spring washers-尊龙凯时网娱乐官网

at present, the main products of 2205 duplex stainless steel in our company are as follows:

outer hexagonal bolts, nuts, washers, etc. welcome to consult

characteristic



1. compared with 316l and 317l austenitic stainless steel, 2205 alloy of duplex stainless steel has better corrosion resistance and crack corrosion resistance. compared with austenite, 2205 alloy has lower thermal expansion coefficient and higher thermal conductivity.

2. compared with austenitic stainless steel, the compressive strength of duplex stainless steel 2205 alloy is twice that of austenitic stainless steel. compared with 316l and 317l, the designer can reduce its weight. 2205 alloy is especially suitable for the temperature range of - 50 f/+600 f. it can also be used at lower temperatures under strict restrictions (especially for welding structures).

chemical composition: c < 0.030, mn < 2.00, si < 1.00, p < 0.030, s < 0.020, cr 22.0-23.0, ni 4.5-6.5, mo 3.0-3.5 n 0.14-0.20 (austenite-ferrite type)

2205 duplex steel

duplex stainless steel 2205 alloy is a composite stainless steel consisting of 21% chromium, 2.5% molybdenum and 4.5% nickel-nitrogen alloy. it has high strength, good impact toughness and good overall and local resistance to stress corrosion.

general attribute

2205 duplex stainless steel is a duplex stainless steel composed of 22% chromium, 3% molybdenum and 5-6% nickel nitrogen. compared with 316l and 317l austenitic stainless steel, 2205 alloy has superior performance in pit corrosion and gap corrosion resistance.

application area

· pressure vessel, high pressure storage tank, high pressure pipeline, heat exchanger (chemical processing industry).

· oil and gas pipelines and heat exchanger fittings.

· sewage treatment system.

· pulp and paper industry classifier, bleaching equipment, storage and processing system.

· rotary shaft, press roll, blade, impeller, etc. in high strength and corrosion resistant environment.

· cargo boxes for ships or trucks

· food processing equipment

standard

astm/asme...a240 uns s32205/s31803

euronorm...... 1.4462 x2crnimon 22.5.3

afnor............... z3 crni 22.05 az

din..................... w. nr 1.4462

corrosion resistance

uniform corrosion

because of the chromium content (22%), molybdenum (3%) and nitrogen content (0.18%), the corrosion resistance of 2205 is better than 316l and 317l in most environments.

local corrosion resistance

the content of chromium, molybdenum and nitrogen in 2205 duplex stainless steel makes it have strong resistance to pitting and gap corrosion in oxidizing and acidic solutions.

stress corrosion resistance

dual-phase microstructure of stainless steel is helpful to improve the stress corrosion cracking resistance of stainless steel. under certain conditions of temperature, tension, oxygen and chloride, chloride stress corrosion will occur in austenitic stainless steel. because these conditions are not easy to control, the use of 304l, 316l and 317l is limited in this respect.

corrosion fatigue resistance

2205 duplex steel has high corrosion fatigue strength due to its high strength and corrosion resistance. processing equipment is vulnerable to corrosion environment and loading cycle, 2205 features are very suitable for such applications.

structure

the ideal microstructures of 2205 can be obtained by solid-melt annealing at 1900 /1922 f (1040 /1080 c). if the temperature of heat treatment is higher than 2000 degrees f, the ferrite composition may increase. like other duplex stainless steels, 2205 alloy is susceptible to precipitation of intermetallic phase. intermetallic phase precipitates between 1300 f and 1800 f. at 1600 f temperature, the precipitation rate is the fastest. therefore, we need to test 2205 to ensure that there is no intermetallic phase. the test refers to astm a 923.

mechanical property

the yield strength at room temperature is 450 mpa, the tensile strength is 620 mpa and the elongation is 25%.

machining

hot forming

it is suggested that the forming should be carried out as far as possible below 600 degrees f. during hot forming, the whole workpiece should be heated as a whole, and should be carried out in the temperature range of 1750 f to 2250 f. 2205 alloy is very soft at this temperature. if the temperature is too high, 2205 alloy is easy to tear. if the temperature is lower than this, the austenite will fracture. when the temperature is lower than 1700 degrees f, the intermetallic phase will form quickly due to the influence of temperature and deformation. after hot forming, it should be annealed immediately at the lowest temperature of 1900 degrees f, and quenched to restore its phase balance, toughness and corrosion resistance. we do not recommend stress relief, but if this is necessary, the material should be annealed at the lowest temperature of 1900 degrees f, then cooled rapidly and quenched by water.

cold forming

2205 alloy can be cut and cold formed. however, because of the high strength and hardness of 2205 alloy, it needs cold forming more than austenitic steel, and because of its high strength, the springback factor should be fully considered.

heat treatment

2205 alloy should be annealed at the lowest temperature of 1900 degrees f, then cooled rapidly and quenched by water. this treatment is applied to solidification annealing and stress relief. stress relief treatment, if carried out at temperatures below 1900 degrees f, can easily lead to the precipitation of harmful metal or non-metal phases.

machinability

on a high-speed machine tool, the feed rate and cutting speed of 2205 alloy are the same as 316l alloy. if the carburizing cutter is used, the cutting speed is reduced by about 20% compared with 316l. the performance of machine equipment and its components plays a key role.

welding

2205 alloy has good weldability. the performance of 2205 alloy is that the welded metal and the heat-modified part remain the same corrosion resistance, strength and toughness as the base metal. the welding of 2205 is not very difficult, but its welding procedure should be designed to maintain good phase balance and avoid harmful metal phase or non-metal phase precipitation after welding. 2205 can be welded in the following equipment: gtaw (tig); gmaw (mig); smaw ("stick" eletrode);saw;fcw;and paw