In a pivotal development for the steel industry, Baosteel and POSCO have successfully invalidated critical patents held by ArcelorMittal and Nippon Steel, significantly reducing patent barriers for Chinese and Korean steelmakers in the hot stamping sector in China.

In May 2024, the Supreme People's Court (SPC) upheld a decision to invalidate ArcelorMittal's hot stamping patent, ZL200680056246.4, dismissing the company's appeal to the Beijing  Intellectual Property Court’s ruling.

This ruling affirmed the 2021 decision by the China National Intellectual Property Administration (CNIPA), which had invalidated the patent due to discrepancies between the patent claims and the specification, especially concerning the cooling rate during stamping.

A key point of contention was Claim 1’s reference to a cooling rate of "at least 50°C/s," while the specification described rates "exceeding 50°C/s," thereby excluding the 50°C/s endpoint. 

Both the Beijing Intellectual Property Court and the Supreme People's Court ruled that patent claims must be supported by the description. In this case, they found that the claim language did not align with the specification, leading to the patent's invalidation.

This patent was reportedly crucial in the hot stamping sector and had been used by ArcelorMittal to dominate the market and frequently sue Chinese companies for infringement.

Baosteel, Shougang Group, POSCO and Easyforming jointly challenged the patent's validity. The Beijing Intellectual Property Court dismissed ArcelorMittal's appeal of CNIPA’s invalidation decision in 2023, and the Supreme People's Court upheld this ruling this May.

Following this, on July 3, the CNIPA declared Nippon Steel’s patent, ZL201280016850.X, invalid due to a lack of innovation.

This patent is related to high-strength, corrosion-resistant hot-pressed components. The invalidation challenge was initiated by Baosteel, POSCO, Lingyun Industrial Corporation Limited, and Easyforming, similar to the previous effort against ArcelorMittal.

Baosteel and Lingyun Industrial Corporation Limited played a crucial role in this case by providing 'public use' evidence. This included the notarized purchase and disassembly of a Fiat 500 in Italy, which proved essential in demonstrating prior use and invalidating the patent.

The invalidation of these patents is significant as it alleviates major patent barriers for Chinese and Korean steelmakers in the competitive hot stamping sector. Additionally, the success in these cases also highlights the importance of precise patent drafting and robust evidence in challenging patents.

As patent barriers fall, Chinese and Korean companies can now more freely innovate and compete in the global steel industry, reducing dependency on technologies previously dominated by ArcelorMittal and Nippon Steel.