Edelstahlschrauben und Verbindungselemente

From 1.4568 to 1.4532:

Change in material for DIN 471/472
retaining rings.

471-472 01.09.2011

 


Starting in September 2011, Lederer will change its warehousing for DIN 471/472 retaining rings in the higher corrosion protection category as follows:

Instead of the previous material 1.4568 only 1.4532 will be stocked in future. Remaining stocks of the articles with "old" material are still available but will not be replaced.

From Lederer´s point of view, the following arguments favour this changeover:

  • The molybdenum component of 2% in the material 1.4532 increases its resistance to pitting and crevice corrosion, particularly where reducing acids and corrosive agents containing chloride are present
  • Dimensional stability, hardness and pliability remain at the same high level.

The DIN 471/472 retaining rings in the lower corrosion protection category are not affected by this change; the material 1.4122 will continue to apply in this area.

 

Supplementary explanatory notes

Comparison of the stainless steel types 1.4532 (X8CrNiMoAI15-7-2) and 1.4568 (X7CrNiAI17-7) to provide a better depiction of the higher corrosion resistance of 1.4532 in connection with the molybdenum content which is present. 

1) 1.4568  = X7CrNiAl17-7 – Ph17-7  

X 7 Cr Ni Al 17 7
high alloy steel 0,07% carbobate content chromium nickel aluminium (approx. 1%) 17% chromium 7% nickel

lower corrosion resistance due to composition excluding molybdenum

2) 1.4532  = X8CrNiMoAl15-7-2 ; Martensitisch – magnetisch, Ph15-7 Mo

X 8 Cr Ni Mo Al 15 7 2
high aloy steel 0,08% carbonate content chromium nickel molybdenum aluminium 0.7-1.5% 15% chromium 7% nickel 2% molybdenum

extremely stable up to 425 °C,highercorrosion resistance due to presence of molybdenum

 

The molybdenum component in the stainless steel 1.4532, when compared with the stainless steel 1.4568, increases this stainless steel type´s protection from reducing acids and corrosive agents containing chloride which occur in, for example, river water. Its durability in the face of pitting and crevice corrosion depends on the chromium and molybdenum content of the material. The molybdenum content and the nickel-molybdenum alloying to which this leads increase the corrosion resistance of 1.4532 (e.g. in relation to stress-corrosion cracking).

 - All information is subject to change, Status: September 2011 -