1.4404 (AISI 316L) with an extra degree of purity
The material 1.4404 VIM, has an improved degree of purity, due to the Vacuum Induction Melting (VIM) process.
Due to the extra degree of purity and the composition of the alloying elements, the material is very resistant to organic (formic acid) and inorganic acids (nitric / sulfuric acid). The resistance to intergranular corrosion is particularly good in aggressive media.
This super-pure material is used in energy technology (e.g. for nuclear applications), in the aviation industry, in the food industry (e.g. for fittings and systems) and in the medical sector.
The stainless steel 1.4404 (AISI 316L) is vacuum induction melted and has a more homogeneous volume and surface structure compared to conventionally manufactured steels. The additional re-melting process reduces the non-metallic impurities (see table).
Non-metallic inclusions acc. ASTM E 45 (Method A) average value, SEMI F20-0706:
Grain size determination of the material 1.4404 (AISI 316L) according to the ASTM E 112 standard.
1.4404 VIM properties:
|Weldability||good, without PWHT|
|Machinability||4 (1 = bad - 10 = good)|
|Impact work||at -70° Celcius over 250 joules|
|Can be used in the temperature range up to 550 ° C|
|Can be polished well|
|Amagnetic quality (μr <1.01)|
|Density in kg/dm³||8,0|
|Thermal conductivity at 20°C in W/(m K)||15|
|Electrical resistance at 20°C (Ω mm2 /m)||0,75|
|Specific heat capacity at 20°C (J/kg K)||500|
|Temperature in °C||Cooling|
|Hot forming||1200 - 900||air, water|
|Solution heat treatment (+AT)||1020 - 1120||water, air|
Forging: before forging, the steel should be heated to 1150°C and 1180°C. The forging process takes place at 1180°C to 900°C with subsequent rapid air or water cooling. Post-treatment of the surface using pickling is recommended.
Welding: 1.4404 steel can be welded with all methods (TIG welding; MAG solid wire, arc welding, SAW welding). The inter-pass temperature should remain below 200°C and a downstream heat treatment (PWHT) is not required.
Cold forming: due to the high work hardening, higher forming forces are required.
Corrosion resistance: the corrosion resistance is increased compared to conventional chrome-nickel-molybdenum steels and the resistance against intergranular corrosion is given.
Machining: due to the high alloy content, machining is more difficult than with bulk steel grades. High-quality high-speed steel or carbide should be used here.
|Cold forming||is possible|
|Cold heading||is possible|
|Open-die and closed-die forging||is possible|
|Machining||possible with caution|
|Machine processing||not possible|
Flat, forged, solution annealed, quenched, outsourced
The processing with the saw is a mechanical processing of the material, which results in a significantly lower unintended deformation and increased hardness for the existing structure, such as the thermal cutting.
Thus, the machined workpiece has a homogeneous structure even at the edge, which does not change in the continuation of the material.
This circumstance allows immediate finishing of the workpiece with milling or drilling . So it is not necessary to anneal the material or make a similar operation beforehand.
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Notice: Specifications contained in following data sheet are provided as a description, liability is excluded!
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