Mold users who buy mold steel based solely on the grade—without considering the quality of the smelting process—will never produce high-quality molds.
For some molds, even when a high-grade mold steel is used, the mold’s service life remains very short. People often assume the problem lies with the steel grade and never question the quality of the smelting process. If everyone adopts this mindset, you’ll never be able to purchase mold steel with the appropriate performance characteristics.
I just received an inquiry from a user who is stamping 0.05-thick nickel sheets. They are currently using powdered high-speed steel, with a stamping speed of 300 strokes per minute, but burrs appear after just 2–3 hours of operation. They asked me what type of die steel to use for stamping nickel sheets, noting that their current grade isn’t working and they want to switch to a different one.
I explained to him that when stamping nickel sheets, the material tends to stick to the die and the parts are prone to flash. Therefore, the top priority for die steel should be non-stick properties, followed by wear resistance. Since he’s already using powdered high-speed steel, his approach is fundamentally correct.
Powder-metallurgic high-speed steel avoids segregation issues and has no microcracks in its microstructure, so it won’t stick to the die or cause stringing. Additionally, since powder-metallurgic high-speed steel is a high-alloy material with high tungsten and vanadium content—and a hardness as high as 64–69 HRC—it offers excellent wear resistance and is more than sufficient for stamping nickel sheets.
The only thing to watch out for is whether the powder-metallurgy high-speed steel you purchased is of high manufacturing quality. If the manufacturing quality is poor and the microstructure exhibits segregation—which can lead to fine cracks—adhesive wear caused by material sticking will occur during the stamping of nickel sheets, resulting in burrs on the product. The short service life of your current die is likely due to the poor manufacturing quality of the die steel you purchased.
This type of adhesive wear caused by material sticking occurs right at the start of the stamping process, yet many people mistakenly assume it is due to insufficient wear resistance of the die steel. This misjudgment will cause your subsequent material selection, thinking, and methods to veer off course.
The factors that determine the performance of die steel are alloy composition, smelting quality, internal structure, heat treatment process, and microstructural state. Do not assume that simply purchasing a specific grade guarantees die performance; nor should you conclude that a particular grade is unsuitable just because the die still malfunctions—this is a misjudgment on your part. It’s like blaming a teacher for poor academic performance instead of examining your own efforts.
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Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.