ASTM A240 Cold Rolled AISI 316Ti DIN1.4571 Stainless Steel Sheet 2.0*1219*2438mm

This data sheet applies to stainless steel 316Ti / 1.4571 hot and cold rolled sheet and strip, semi-finished products, bars and rods, wire and sections as well as for seamless and welded tubes for pressure purposes.

Application

Construction encasement, doors, windows and armatures, off-shore modules, container and tubes for chemical tankers, warehouse and land transportation of chemicals, food and beverages, pharmacy, synthetic fibre, paper and textile plants and pressure vessels. Due to the Ti-alloy, resistance to intergranular corrosion is guaranteed after welding.

Chemical Compositions*

Mechanical properties (at room temperature in annealed condition)

Reference data on some physical properties

Coefficient of linear thermal expansion 10-6 K-1 between 20°C and

Processing / Welding

Standard welding processes for this steel grade are:

• TIG-Welding
• MAG-Welding Solid Wire
• Arc Welding (E)
• Laser Beam Welding
• Submerged Arc Welding (SAW)

When choosing the filler metal, the corrosion stress has to be regarded, as well. The use of a higher alloyed filler metal can be necessary due to the cast structure of the weld metal. A preheating is not necessary for this steel. A heat treatment after welding is normally not used. Austenitic steels only have 30% of the thermal conductivity of non-alloyed steels. Their fusion point is lower than that of non-alloyed steels therefore austenitic steels have to be welded with lower heat input than on-alloyed steels. To avoid overheating or burn-through of thinner sheets, higher welding speed has to be applied. Copper back-up plates for faster heat rejection are functional, whereas, to avoid cracks in the solder metal, it is not allowed to surface-fuse the copper back-up plate. This steel has an extensively higher coefficient of thermal expansion as non-alloyed steel. In connection with a worse thermal conductivity, a greater distortion has to be expected. When welding 1.4571 all procedures, which work against this distortion (e.g. back-step sequence welding, welding alternately on opposite sides with double-V butt weld, assignment of two welders when the components are accordingly large) have to be respected notably. For product thicknesses over 12mm the double-V butt weld has to be preferred instead of a single-V butt weld. The included angle should be 60° - 70°, when using MIG-welding about 50° is enough. An accumulation of weld seams should be avoided. Tack welds have to be affixed with relatively shorter distances from each other (significantly shorter than those of non-alloyed steels), in order to prevent strong deformation, shrinking or flaking tack welds. The tacks should be subsequently grinded or at least be free from crater cracks. 1.4571 in connection with austenitic weld metal and too high heat input the addiction to form heat cracks exists. the addiction to heat cracks can be confined, if the weld metal features a lower content of ferrite (delta ferrite). Contents of ferrite up to 10% have a favourable effect and do not affect the corrosion resistance generally. The thinnest layer as possible has to be welded (stringer bead technique) because a higher cooling speed decreases the addiction to hot cracks. A preferably fast cooling has to aspired while welding as well, to avoid the vulnerability to intergranular corrosion and embrittlement. 1.4571 is very suitable for laser beam welding (weldability A in accordance with DVS bulletin 3203, part 3). With a welding groove width smaller than 0.3mm respectively, 0.1mm product thickness the use of filler metals is not neecessary. With larger welding grooves a similar metal can be used. With avoiding oxidation with the seam surface during laser beam welding by applicable backhand welding, e.g. Helium as inert gas, the welding seam is as corrosion resistant as the base metal. A hot crack hazard for the welding seam does not exist, when choosing an applicable process. 1.4571 is also suitable for laser beam fusion cutting with nitrogen or flame cutting with oxygen. The cut edges only have small heat affected zones and are generally free of micro cracks and thus are well formable. While choosing an applicable process the fusion cut edges can be converted directly. Especially, they can be welded without any further preparation. While processing only stainless tools like steel brushes, pneumatic picks and so on are allowed, in order to not endanger the passivation. It should be neglected to mark within the welding seam zone with oleigerous bolts or temperature indicating crayons. The high corrosion resistance of this stainless steel is based on the formation of a homogeneous, compact passive layer on the surface. Annealing colours, scales, slag residues, tramp iron, spatters and such like have to be removed, in order to not destroy the passive layer. For cleaning the surface the processes brushing, grinding, pickling or blasting (iron-free silica sand or glass spheres) can be applied. For brushing only stainless steel brushes can be used. Pickling of the previously brushed seam area is carried out by dipping and spraying, however, often pickling pastes or solutions are used. After pickling a careful flushing with water has to be done.