Changfu DONG

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Shanghai, CN

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Patents Grantslast 30 patents

Information Patent Grant
Method for manufacturing superior 13Cr friction-welded drillrod
- Patent number 9,988,857
- Issue date Jun 5, 2018
- Baoshan Iron & Steel Co., Ltd.
- Peng Zhao
- B23 - MACHINE TOOLS METAL-WORKING NOT OTHERWISE PROVIDED FOR

Patents Applicationslast 30 patents

Information Patent Application
METHOD FOR MANUFACTURING SUPERIOR 13CR FRICTION-WELDED DRILLROD
- Publication number 20160076315
- Publication date Mar 17, 2016
- Baoshan Iron & Steel Co., Ltd
- Peng ZHAO
- C21 - METALLURGY OF IRON