W.Nr. 1.4958、X5NiCrAlTi31-20、NA15(H)

Overview of W.Nr. 1.4958corrosion-resistant alloy:

W.Nr. 1.4958 can withstand many corrosive media. Its higher nickel content makes it have good resistance to stress corrosion cracking in water-based corrosion conditions. The high chromium content makes it better resistant to pitting corrosion and crevice corrosion cracking. The alloy has good corrosion resistance to nitric acid and organic acids, but the corrosion resistance in sulfuric acid and hydrochloric acid is limited. In addition to the potential for pitting corrosion in halides, it has good corrosion resistance in oxidizing and non-oxidizing salts. It also has good corrosion resistance in water, steam and mixtures of steam, air and carbon dioxide. The Cr content of W.Nr. 1.4958 alloy is usually 15-25%, the nickel content is 30-45%, and contains a small amount of aluminum and titanium. The W.Nr. 1.4958 alloy is in a single austenite zone after rapid cooling at high temperature, therefore, the use state is a single austenite structure. The alloy has a higher chromium content and sufficient nickel content, so it has higher high temperature corrosion resistance and is used more in industry. In chloride, low concentration NaOH aqueous solution and high temperature and high pressure water, it has excellent resistance to stress corrosion cracking, so it is used to manufacture stress corrosion cracking resistant equipment.

 

Chemical composition of W.Nr. 1.4958 corrosion-resistant alloy:

%	Cr	Ni	Mn	Si	Al	Ti	C	Cu	P	S
Min.	19.0	30.0			0.15	0.15	0.05
Max.	23.0	35.0	1.5	1.0	0.60	0.60	0.10	0.75	0.03	0.015

 

W.Nr. 1.4958 corrosion resistance alloy physical properties:

Density	8.0 g/cm3
Melting point	1350-1400 ℃

 

Mechanical properties of W.Nr. 1.4958 corrosion-resistant alloy at room temperature:

tensile strength Rm N/mm2	yield strength RP0.2N/mm2	Elongation A5 %
450	180	35

 

W.Nr. 1.4958 corrosion-resistant alloy has the following characteristics:

● Excellent corrosion resistance in extremely high temperature aqueous media up to 500 ℃

● Good resistance to stress corrosion

● Good workability

 

W.Nr. 1.4958corrosion-resistant alloy metallographic structure:

W.Nr. 1.4958 is a face-centered cubic lattice structure. The extremely low carbon content and the increased Ti: C ratio increase the structural stability and anti-sensitization and intergranular corrosion resistance. Low-temperature annealing around 950 ° C ensures a fine-grained structure.

 

W.Nr. 1.4958 corrosion resistance alloy properties:

W.Nr. 1.4958 can withstand many corrosive media. Its higher nickel content makes it have good resistance to stress corrosion cracking in water-based corrosion conditions. The high chromium content makes it better resistant to pitting corrosion and crevice corrosion cracking. The alloy has good corrosion resistance to nitric acid and organic acids, but the corrosion resistance in sulfuric acid and hydrochloric acid is limited. In addition to the potential for pitting corrosion in halides, it has good corrosion resistance in oxidizing and non-oxidizing salts. It also has good corrosion resistance in water, steam and mixtures of steam, air and carbon dioxide.

 

W.Nr. 1.4958corrosion resistance alloy process performance and requirements:

Thermal processing

1. The temperature range is 1200 ℃ ～ 950 ℃, and the cooling method is water quenching or rapid air cooling.

2. In order to obtain performance and creep resistance, solution treatment should be carried out after hot processing.

3. The material can be directly fed into the furnace which has been heated up to 1200 ℃. After sufficient heat preservation time, it can be quickly released and hot-processed in the specified temperature range. When the material temperature drops below the hot working temperature, it needs to be reheated.

Cold working

1. The work hardening rate is greater than that of austenitic stainless steel, so the processing equipment needs to be selected. The cold-worked material should be in the state of solution heat treatment, and intermediate annealing should be performed when the amount of cold work is large.

2. If the cold working volume is greater than 10%, the workpiece needs to be subjected to secondary solution treatment.

 

W.Nr. 1.4958corrosion-resistant alloy welding process:

Suitable for welding with the same material or other metals using any traditional welding process, such as tungsten electrode inert gas shielded welding, plasma arc welding, manual sub-arc welding, metal inert gas shielded welding, molten electrode inert gas shielded welding, including pulsed arc welding Is the plan. If manual arc welding is used, (Ar + He + H2 + CO2) is recommended as shielding gas.

 

W.Nr. 1.4958 corrosion-resistant alloy application scope Application areas are:

1. Nitric acid condenser-nitric acid corrosion resistance

2. Steam heating tube-very good mechanical properties

3. Heating element tube-very good mechanical properties

For applications up to 500 ℃