1.4571/316 Ti

Stainless steel EN 1.4571/ AISI 316 Ti (UNS S31635, but sometimes referred to as VA4) is a titanium stabilized austenitic chromium-nickel-molybdenum stainless steel. The material is used as an alternative for 1.4404 / AISI 316L when resistance and strength at high temperatures are required. Intergranular corrosion resistance of 1.4571 is improved with the addition of titanium, which prevents precipitation of chromium carbides in the grain boundaries. The 1.4571 is known for its good resistance to corrosion in most natural water (urban and industrial), provided that the concentration of chloride and hydrochloric acid is not too high.

• Chemical Industry
• Construction industry
• Food industry (transport and storage of food)
• Mechanical engineering
• Medical and pharmaceutical industry
• Shipbuilding

• AISI 316 Ti / SS 2350 / UNS 31635 / UNS S31635
• AFNOR Z6CNDT17-12 / BS 320S17 / UNI X6CrNiMoTi1712 / JIS SUS316TI / GOST 10Ch17N13M2T
• ASTM A 240 / A 276
• German Material no.: 1.4571
• X5CrrrNiCuNb17-4-4

Material may also be supplied against Customer specifications, subject to enquiry.

Chemical Composition, %

• Tensile Strength – 72.5 ksi to 101.5 ksi
• Yield Strength – ≥ 200 MPa
• Elongation – ≥ 40%
• Hardness – 215 max HB
• Modulus of Elasticity – 200 GPa

316 Ti exhibits good corrosion resistance in environments containing low to medium concentrations of chlorides, salts and various organic acids. However, hydrochloric acid (HCl) is highly aggressive to all stainless-steel grades and should be avoided unless handled under strictly controlled conditions.

While AISI 316Ti is developed for use at higher temperatures, it is able to maintain toughness at lower temperatures as well. Machinability of the grade is moderate, but very weldable by most standard processes and post-weld heat treatment is generally not necessary.

Weldability: excellent
Machinability: 4 (1 = poor – 10 = good)
Polishability: not possible
Corrosion class: 4 (0 = poor – 5 = good)

Due to the presence of titanium, tool wear is higher in 316Ti than in comparable chromium-nickel-molybdenum steels. While 316Ti generally offers fair to moderate machinability, the use of carbide tools is recommended to improve tool life. Performance will improve with these proper cutting techniques:

• Use sharp cutting edges to minimise work hardening.
• Apply deep, steady cuts to avoid glazing or riding on the material surface.
• Chip breakers should be used to manage swarf and improve efficiency.
• Due to low thermal conductivity, coolants/lubricants are essential and should be applied generously to avoid overheating.

316Ti offers good corrosion resistance across various environments. It resists intergranular corrosion in both as-delivered and welded states and performs well in low-salt, low-chlorine conditions.

However, it is not truly resistant to continuous seawater exposure (despite being marketed as “marine grade”). Warm chloride environments can induce pitting and crevice corrosion, and Grade 316 is susceptible to stress corrosion cracking above approximately 60°C.