Ultra austenitic stainless steel 904L

Process performance:
Like other common Cr-Ni austenitic steels, it has good cold and hot working properties.
The maximum hot forging temperature is 1180 degrees Celsius, and the minimum stop temperature is not less than 900 degrees Celsius.
This steel can be thermoforming at 1000--1150 degrees Celsius.
The heat treatment process of the steel is 1100--1150 degrees Celsius, and it is quickly cooled after heating.
Although the steel can be welded by the general welding process, the most appropriate welding methods are manual arc welding and argon tungsten arc welding.
When manual arc welding is not more than 6 mm plate welding rod diameter is not more than 2.5 mm; When the plate thickness is greater than 6 mm, the electrode diameter is less than 3.2 mm. When the heat treatment is needed after welding, it can be processed at 1075--1125 degrees Celsius after heating and fast cooling.
The filling metal for GTAW welding can be the same material electrode, and the weld shall be pickled and passivated after welding.
Corrosion resistance
00Cr20Ni25Mo4.5Cu steel is mainly developed to solve the corrosion of sulfuric acid. [11]
At the same time, it is also resistant to the corrosion of acetic acid at any concentration and temperature under atmospheric pressure.
It also has good corrosion resistance in formic acid, phosphoric acid, and mixed acid of formic acid and acetic acid.
The results of testing the intergranular corrosion tendency of OOCr20Ni25Mo4.5Cu steel by GB1223-75 medium T method show that when the steel contains C0.038%, the intergranular corrosion of the steel needs to be sensitized for more than 1 hour. Therefore, even if the welding thickness is less than 30mm, as long as the welding process is appropriate, there is no danger of intergranular corrosion. The results of pitting potential and pitting test show that 00Cr20Ni25Mo4.5Cu is superior to 00Cr18Ni10 and 00Cr18Ni14Mo2 cr-Ni austenitic steel.
The stress corrosion resistance of 00Cr20Ni25Mo4.5Cu steel is better than that of cr-Ni austenitic steel because the Ni content in 00Cr20Ni25Mo4.5Cu steel is 25%.
In general, when stress corrosion cracking occurs with 18-8, 18-12-Mo stainless steel in aqueous media containing chloride ions, 00Cr20Ni25Mo4.5Cu is often selected to prevent the occurrence of accidents.