1.2316 ESR Steel: ESR Upgrades High-Grade Steel

What is 1.2316 ESR Steel?

ESR (Electroslag Remelting) stands for a secondary refining process. The production flow of standard 1.2316 goes through medium frequency furnace melting, LF refining, VD vacuum degassing, ingot casting and forging. For 1.2316 ESR steel, one extra step is added in the whole flow: cast ingots act as consumable electrodes and remelt through molten slag inside an ESR furnace. Liquid steel passes through high-temperature slag in tiny droplets, a micro-level filtering and cleaning process. The slag traps and absorbs oxide and sulfide impurities inside the steel, and the purified liquid steel solidifies into dense ESR ingots in the water-cooled mold at the bottom. After ESR treatment, sulfur content drops from the regular level of ≤0.020% down to ≤0.005%, inclusion rating is greatly reduced, and segregation is obviously improved.

Six Major Performance Improvements of 1.2316 ESR Steel

• Higher purity: Non-metallic inclusions are reduced by 50–70%, which is vital for mirror polish and transparent plastic molds, as invisible tiny inclusions on polished surfaces are mostly removed in ESR steel.
• Uniform microstructure: ESR eliminates central segregation of ordinary ingots, distributes carbides evenly and delivers more stable hardness.
• Better fatigue resistance: Inclusions cause fatigue cracks; fewer impurities greatly extend the mold’s thermomechanical fatigue life.
• Excellent polishing capacity: DIN 1.2316 ESR steel has far fewer surface defects after polishing and can reach superior surface smoothness.
• Even corrosion resistance: Uniform structure forms an equally thick passive film to avoid local weak corrosion areas.
• Higher ultrasonic testing pass rate: ESR ingots own compact interior with fewer internal UT defects.

Cost and Return of 1.2316 ESR Steel

1.2316 ESR steel costs around 30-50% more than standard 1.2316. Whether the extra cost is worthwhile depends on your mold application. It is worth the premium for mirror polish molds such as transparent PC lamp molds and optical lens molds, where polishing defects caused by inclusions are critical flaws and ESR grade is nearly mandatory; precision molds requiring long service life, as if a mold needs to run over 500,000 shots, the extra cost of ESR spread over each finished part is negligible; medical device and implant molds that demand zero-defect high purity, making ESR a necessary option. It is not recommended to pay extra for ordinary plastic molds without mirror finish requirements and production output below 200,000 shots, or non-cosmetic molds, because upgraded standard 1.2316 refined by LF+VD treatment delivers excessive performance for these scenarios. The core judging rule is simple: pick ESR if your molds mostly fail due to poor polishing quality or cracks triggered by inclusions; standard grade is sufficient if mold failure only comes from regular wear.

How to Verify Genuine 1.2316 ESR Steel

• Check material test certificate: Authentic 1.2316 ESR Steel is clearly marked “ESR” or “Electroslag Remelted” under the process section, with sulfur content controlled ≤0.005%, while standard 1.2316 only requires ≤0.020%. This is the most reliable indicator.
• Check inclusion rating: Tested per ASTM E45 or ISO 4967, ESR grade shows much lower ratings for both thin and thick series non-metallic inclusions.
• Check ultrasonic test result: ESR ingots display cleaner UT waveforms with far fewer flaw echoes compared to conventional cast ingots.

Be cautious if the supplier cannot provide at least one of the above proofs, especially sulfur content test data. Genuine DIN 1.2316 ESR from official suppliers comes with full process traceability and complete quality documents.

Typical Sizes and Delivery of 1.2316 ESR Steel

The available delivery dimensions of 1.2316 ESR mold steel are similar to standard 1.2316. However, the size of ESR ingots is limited by ESR furnace capacity, so the supply capacity of large cross-section bars relies on the steel mill’s equipment. Regular available sizes include plates with thickness from 10 to 300 mm and round bars with diameter from 10 to 500 mm. Materials thicker than 200 mm are recommended to adopt the ESR + upsetting and drawing process to guarantee core internal quality. Two delivery conditions are optional: pre-hardened state at 28–34 HRC or annealed state at 20–25 HRC for customers to conduct heat treatment independently. The annealed state is more common for ESR grade, since customers who select ESR steel usually have customized heat treatment requirements, such as quenching to 40–48 HRC for high wear-resistant molds, and there is no need for mills to pre-harden and then re-anneal the material. Confirm the supplier’s ESR equipment capacity and quality management system before purchasing, as ESR processing quality varies widely among different steel manufacturers.