HiFIT - High Frequency Impact Treatment

REVOLUTION FOR WELDED CONSTRUCTIONS

THE HiFIT POST-WELD TREATMENT is a high frequency mechanical impact treatment method that significantly increases the durability and service life of dynamically loaded, welded steel constructions via the targeted post-treatment of weld transitions.

ADVANTAGES

The advantages of HiFIT post-weld treatment is impressive and result in an enormous increase in the economic efficiency of your welded constructions. Below you will find the summary from the Refresh project which is funded by the German Federal Ministry of Education and Research.

%80 – %100 INCREASE IN WELD FATIGUE LIMIT

-The weld transition is geometrically rounded.

-The weld transition is plastically deformed and strengthened via local reshaping.

-Internal compression stresses prevent crack formation and crack propagation at the surface.

5- TO 15- FOLD INCREASE IN WELD SERVICE LIFE

-Over 1000 tests have shown a multiple increase in the service life.

IIW RECOMMENDATIONS FOR THE HFMI TREATMENT

XIII. Commission of International Institute for Welding (IIW) presented 46 documents that verify the improvement in welded constructions.

The IIW Guideline for HFMI describes the method, its application and quality inspection. The guideline also provides informative design examples, one of them shown below.

DESIGN EXAMPLE

A welded joint made from a material with f < 355 MPa is classified as FAT class 63. The max. load range is 63 MPa for 2 x 10⁶load cycles. (see Fig.2)

Via the HiFIT method, the FAT class increases by 4 levels (see Fig.1, blue arrow) to FAT 100, the permissible load range is now 100MPa. This is an increase of approx. 60% !

For the same load range (63 MPa), the service life is increased from 2 m to 40 m load cycles ! This is a factor of 20. (seeFig.2)