SSUS444 (00Cr18Mo2) is a super low carbon nitrogen, 18% chromium and 2% molybdenum, high corrosion resistant ferrite stainless steel. The steel is usually stabilized with niobium or titanium to avoid intergranular corrosion after welding. The steel is especially suitable for various water treatment devices.
ASTM A268 / A268M :Standard Specification for Seamless and Welded Ferritic and Martensitic Stainless Steel Tubing for General Service
SUS444 steel belongs to high alloy ferrite stainless steel, compared with the commonly used steel SUS430:
1. The content of chromium is about 1.0% higher and the alloy element Mo is added. Therefore, the steel has good resistance to pitting corrosion, crevice corrosion and stress corrosion, and its corrosion resistance is even better than SUS304 and SUS316 in some fields.
2. Stabilizing elements such as Ti, Nb and Zr are added, so the steel has good intergranular corrosion resistance and high temperature oxidation resistance.
chemical composition
Carbon C: less than 0.025
Silicon Si: less than 1
Mn Mn: less than 1
Sulfur S: less than 0.030
Phosphorus P: less than 0.040
Chromium Cr:17.00~20.00
Nickel Ni: (less than 0.60)
Molybdenum Mo:1.75~2.50
Nitrogen N: less than 0.025
Titanium + Nb + Zr Ti+Nb+Zr:=8*C = 0.8
SUS444 has ultra-low carbon and nitrogen impurity elements.
SUS444 added molybdenum element to increase the resistance to spot corrosion.
SUS444 added NB or Ti with stabilizing effect.
SUS444 steel belongs to high alloy ferritic stainless steel. Compared with SUS430 steel, it contains about 1.0% more chromium and adds molybdenum (Mo), so it has good resistance to pitting corrosion, crevice corrosion and stress corrosion, and its corrosion resistance is even better than SUS304 and SUS316 in some fields. 2. Stabilizing elements such as Ti, Nb and Zr are added, so the steel has good intergranular corrosion resistance and high temperature oxidation resistance. 2, use
The yield strength of SUS444 is 1.5 times as high as that of carbon steel and 6 times as high as that of glass fiber reinforced plastics. SUS444 ferritic stainless steel has high thermal conductivity, about 130%-150% of that of chromium-nickel austenitic stainless steel, which is very suitable for heat exchange. The element is only 60%-70% of chromium-nickel austenitic stainless steel, which is very suitable for use in hot swelling, cold shrinkage and thermal cycling conditions. The steel has good plasticity and toughness, is suitable for drawing, rolling and stamping. Especially, corrosion resistance is the best in application, and its corrosion resistance in high chloride medium is superior to that of ordinary ferrite. The corrosion resistance to pitting and crevice corrosion is improved by adding Ni, Ti, Mo elements. The steel can be welded by welding ordinary stainless steel. The steel is especially suitable for food processing equipment, heat exchangers, water heater tanks, water storage tanks, etc. Solar energy collection panel and so on.
ASTM A268 / A268M :Standard Specification for Seamless and Welded Ferritic and Martensitic Stainless Steel Tubing for General Service