A customer purchasing cold-forging dies for IGBT copper heat sinks has once again placed an order with Yuhui for 24 pieces of high-toughness LG die steel.
Behind every customer lies a story. This customer manufactures cold-forging dies for IGBT red copper heat sinks. Clients in this industry typically have substantial financial resources. Even the smallest investment—purchasing two 5,000-metric-ton forging presses—costs over 1 million yuan, and a single set of dies runs into the hundreds of thousands. That’s 2 million yuan invested before a single product has even been produced.
I’m delighted not only because this client places large orders, but also because he has high quality standards and the financial means to meet them. Cold-forging dies for copper heat sinks involve directly cold-forging columns from copper sheets, which places extremely high demands on the strength and toughness of the die steel. The upper die has many holes, and the overlap between them is very small. If the die steel lacks toughness, it’s prone to cracking; if the hardness is too low, it’s prone to collapse and tearing. The requirements for the strength and toughness of the die steel are extremely high.
The lower die must withstand thousands of metric tons of pressure, so the requirements for its strength and toughness are also high. If the hardness is too low, the four corners will cave in, resulting in inconsistent corners on the pressed product, which increases the amount of subsequent processing required and may even lead to non-conforming products. If the toughness is insufficient, the die will crack, making it even less cost-effective. Previously, they used DC53, but its toughness was too poor and it was prone to cracking; H13 lacked sufficient strength and was prone to collapse, so they could never find a suitable material.
In contrast, LG has a hardness of 54–58 HRC and a toughness 8–9 times that of DC53—so tough that it won’t break even if you bend it by hand. Both the perforated upper die and the ejector pins below are made from high-toughness LG die steel, which offers sufficient strength and excellent toughness. This time, the customer purchased another 24 pieces.
The customer’s willingness to make bulk and long-term purchases is a testament to the quality and performance of your mold steel. It indicates that the mold life is sufficient; otherwise, the customer wouldn’t make such bulk purchases—buying more than twenty pieces at a time.
LG die steel has 8–9 times the toughness of DC53 and a hardness of 54–58 HRC; it’s so tough that it won’t break even if you bend it by hand. If you’re using other mold steels for cold forging or cold extrusion dies for your IGBT copper heat sinks—and they tend to stick to copper powder or crack easily, leaving you with no solution—or if the mold steel you’re currently using has a short service life and you’re unsure which material to choose, then you should try the high-toughness LG mold steel.
Use LG die steel to solve mold cracking issues—it’s like stepping into a liberated zone.
*************
Wu Dejian’s tool steel, the chief of staff of the user, bought everything he had used.