The goal of using ESR is to eliminate internal defects that could act as initiation points for fatigue cracks.

Key Drivers for ESR Impeller Blanks:

Elimination of Inclusions: Even tiny non-metallic inclusions in a forged blank can be the origin of a fatigue crack under high-cycle fatigue conditions.

Improved Toughness and Ductility: Cleaner metal with lower sulfur content has better impact resistance and fracture toughness.

Homogeneity: Consistent properties throughout the entire disk are critical for predictable performance and stress analysis.

High-Pressure & Critical Service: For compressors in:

Oil & Gas (API 617 standard often specifies ESR for critical impellers)

Petrochemical and LNG (liquefaction service)

Air Separation Units (ASU)

High-pressure process air

The electroslag process for centrifugal impeller rough blanks is a premium materials engineering solution for the most demanding compressor applications.

It trades higher initial cost for:

Maximum reliability and safety.

Extended service life, especially under cyclic loading.

Compliance with stringent industry standards (like API 617).

It ensures that the rotating component has the highest possible internal integrity, minimizing the risk of fatigue failure originating from material defects. For an OEM or end-user where unplanned downtime is immensely costly or hazardous, specifying an ESR impeller is a wise investment.