This thread talks about the MiG-23's №2 fuel tank made of special stainless steel called VNS-2, used before 1964. It’s strong, corrosion-resistant, and tough, with a capacity of 870 liters. The thread also covers different metal alloys used in aircraft, their history, and maintenance details like lubricants. Plus, it highlights cool facts about the MiG-23 and related aircraft.
MiG-23 №2 fuel tank🧵
The MiG-23's №2 fuel tank is made of VNS-2 martensitic precipitation-hardening stainless-steel (PHSS). It had a 870 litre capacity and was manufactured by electric arc welding at the Tushino Plant №82, then shipped to Lukhovitsy for aircraft assembly.
The material's corrosion resistance is provided by the ≈15% Cr, precipitation hardening provided by the Cu, and probably by the Ni & Ti intermetallic compounds. The USA's version is 15-5PH, which substitutes Ti for Nb/Ta in the same role, probably reflecting the availability...
...of these elements in both countries. In the US, the first comercial PHSS was 17-4PH in 1948, developed by Armco, with a simple heat treatment regime and acceptable weldability, allowing its use in aircraft landing gears, manufacturing fasteners, and engine parts.
blog.cwam.
Unfortunately, it also had limited cold formability & low impact toughness. Then came the tougher 15-5PH in 1965 reducing the content of Cr element and increasing the content of Ni. In 1968 came the further improved 13-8PH which replaced the Cu & Nb/Ta with Mo & Al.
When did VNS-2 first appear in the USSR is unknown to me, but it had to have been before the first flight of the MiG-25, 6th of March 1964, then being a new material. So Foxbat used VNS-2 as well, but as thin welded sheet metal. As can be seen here:
The ultimate tensile strength of VNS-2, from what I've seen ranges from 880 to 1470 MPa, most common figure being 1230 MPa depending on heat treatment and stock gauge.
According to the MiG-23M structural description book from 1972:
The lubricant used is called Svintsol-01 (Свинцоль-01), which is TsIATIM-201 with the addition of 10% lead powder. TsIATIM-201 is an antifriction, lithium lubricant composed of a mixture of low-viscosity petroleum oil, a thickener (lithium stearate) & an antioxidant additive.
A US equivalent would be AeroShell Grease 33MS. You can see here Dallas Cold War Air Museum Director, Jon Boede, applying it to the bronze bushing.
The museum's blog page has many photos of their MiG-23UB being worked on. I recommend you give it a visit if you're in to that sort of thing at
MiG-23 №2 fuel tank🧵
The MiG-23's №2 fuel tank is made of VNS-2 martensitic precipitation-hardening stainless-steel (PHSS). It had a 870 litre capacity and was manufactured by electric arc welding at the Tushino Plant №82, then shipped to Lukhovitsy for aircraft assembly.The material's corrosion resistance is provided by the ≈15% Cr, precipitation hardening provided by the Cu, and probably by the Ni & Ti intermetallic compounds. The USA's version is 15-5PH, which substitutes Ti for Nb/Ta in the same role, probably reflecting the availability......of these elements in both countries. In the US, the first comercial PHSS was 17-4PH in 1948, developed by Armco, with a simple heat treatment regime and acceptable weldability, allowing its use in aircraft landing gears, manufacturing fasteners, and engine parts.
blog.cwam.Unfortunately, it also had limited cold formability & low impact toughness. Then came the tougher 15-5PH in 1965 reducing the content of Cr element and increasing the content of Ni. In 1968 came the further improved 13-8PH which replaced the Cu & Nb/Ta with Mo & Al.When did VNS-2 first appear in the USSR is unknown to me, but it had to have been before the first flight of the MiG-25, 6th of March 1964, then being a new material. So Foxbat used VNS-2 as well, but as thin welded sheet metal. As can be seen here:The ultimate tensile strength of VNS-2, from what I've seen ranges from 880 to 1470 MPa, most common figure being 1230 MPa depending on heat treatment and stock gauge.According to the MiG-23M structural description book from 1972:The lubricant used is called Svintsol-01 (Свинцоль-01), which is TsIATIM-201 with the addition of 10% lead powder. TsIATIM-201 is an antifriction, lithium lubricant composed of a mixture of low-viscosity petroleum oil, a thickener (lithium stearate) & an antioxidant additive.A US equivalent would be AeroShell Grease 33MS. You can see here Dallas Cold War Air Museum Director, Jon Boede, applying it to the bronze bushing.The museum's blog page has many photos of their MiG-23UB being worked on. I recommend you give it a visit if you're in to that sort of thing atThat wing pin really weighs a lot!
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MiG-23 №2 fuel tank🧵
The MiG-23's №2 fuel tank is made of VNS-2 martensitic precipitation-hardening stainless-steel (PHSS). It had a 870 litre capacity and was manufactured by electric arc welding at the Tushino Plant №82, then shipped to Lukhovitsy for aircraft assembly. ... The material's corrosion resistance is provided by the ≈15% Cr, precipitation hardening provided by the Cu, and probably by the Ni & Ti intermetallic compounds. The USA's version is 15-5PH, which substitutes Ti for Nb/Ta in the same role, probably reflecting the availability... ... ...of these elements in both countries. In the US, the first comercial PHSS was 17-4PH in 1948, developed by Armco, with a simple heat treatment regime and acceptable weldability, allowing its use in aircraft landing gears, manufacturing fasteners, and engine parts.
blog.cwam. ... Unfortunately, it also had limited cold formability & low impact toughness. Then came the tougher 15-5PH in 1965 reducing the content of Cr element and increasing the content of Ni. In 1968 came the further improved 13-8PH which replaced the Cu & Nb/Ta with Mo & Al. ... When did VNS-2 first appear in the USSR is unknown to me, but it had to have been before the first flight of the MiG-25, 6th of March 1964, then being a new material. So Foxbat used VNS-2 as well, but as thin welded sheet metal. As can be seen here: ... The ultimate tensile strength of VNS-2, from what I've seen ranges from 880 to 1470 MPa, most common figure being 1230 MPa depending on heat treatment and stock gauge. ... According to the MiG-23M structural description book from 1972: ... The lubricant used is called Svintsol-01 (Свинцоль-01), which is TsIATIM-201 with the addition of 10% lead powder. TsIATIM-201 is an antifriction, lithium lubricant composed of a mixture of low-viscosity petroleum oil, a thickener (lithium stearate) & an antioxidant additive. ... A US equivalent would be AeroShell Grease 33MS. You can see here Dallas Cold War Air Museum Director, Jon Boede, applying it to the bronze bushing. ... The museum's blog page has many photos of their MiG-23UB being worked on. I recommend you give it a visit if you're in to that sort of thing at ... That wing pin really weighs a lot!
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