Pacific Rim Enterprises works with stainless steels grades with different corrosion resistance and mechanical properties. Pacific Rim Enterprises will select these carefully for your specific application to ensure system performance. The Stainless Steel Grades used include:
- 200 Series – This group of alloys contains 17% chromium, 4% nickel, and 7% manganese and has similar properties to the 300 Series (below). These are non-magnetic and have an austenitic structure that make it more resistant to attack than the more commonly used 300 Series. These alloys are not immune to attack as they are susceptible to concentration cell corrosion and pitting corrosion, which will usually occur rapidly and in a sporadic way. Some proprietary grades in the 200 Series are equal to or even superior to the best Stainless Steel grades in the 300 Series. When submerged in seawater, the incubation time for the alloys in this series is between one and three months; however some nitronic grades have incubation times of up to one year.
- 300 Series – This group of alloys contain 18% chromium and 8% nickel and are also non-magnetic containing an austenitic structure making it more resistant to attack. Although these alloys are susceptible to crevice corrosion and pitting corrosion, they have been widely used in facilities with mixed results. This series of alloys will perform well when used in an application where either chloride levels are low or where through design, concentration cell corrosion has been prevented. On the other hand, they will perform poorly when chlorine levels are high and where concentration cell corrosion can occur. The incubation time in seawater can range from zero (free machining grades such as Type 303) to six months to one year (best alloys such as Type 316). These alloys must be carefully selected for specific applications and the effect of potential, non-uniform attack on system performance must be addressed.
- 400 Series – This group of alloys contain 11% chromium and 1% magnesium. They are magnetic and have martensitic structure. These alloys can be heat- treated and hardened but perform poorly in terms of corrosion resistance. In seawater, this series is subject to both uniform and non-uniform attack with an extremely short incubation time in chloride environments, sometimes a few days or even just hours. Pacific Rim Enterprises does use these grades in seawater or other environments that are susceptible to corrosion.
- 600 Series – This series of stainless steels grade can be heat-treated to extremely high strength levels. This series is subject to crevice corrosion and pitting in chloride environments and are also subject to stress corrosion cracking and hydrogen embrittlement (aka precipitation hardening). The incubation time for crevice corrosion and pitting in seawater is relatively short, sometimes in just a few days. The incubation time for stress corrosion cracking can be even shorter, many time in just a few hours. The use of these grades is not normally recommended unless their heat treatment is specified and controlled,and the effect of crevice corrosion and pitting is carefully and properly addressed.
Call us or contact us for any order or assistance:
Phone: (800) 928-9108
Fax: (516) 797-1819
1517 Lakeshore Drive
New York, 11762