High-strength hydrogen embrittlement-resistant diaphragm with mark of MP-7 and preparation method of high-strength hydrogen embrittlement-resistant diaphragm

Abstract

The invention relates to the field of key material parts of hydrogen energy equipment, in particular to a high-strength hydrogen embrittlement-resistant diaphragm with the mark of MP-7 and a preparation method. The diaphragm comprises the following chemical components in percentage by weight: 29.50 to 31.50 percent of Ni, 14.00 to 16.00 percent of Cr, 0.90 to 1.50 percent of Mo, 0.10 to 0.40 percent of V, 1.80 to 2.40 percent of Ti, 0.60 to 0.80 percent of Al, 0.001 to 0.0030 percent of B and the balance of Fe. According to the preparation method, high strength and hydrogen embrittlement resistance of the diaphragm are ensured based on introduction of a nanoscale gamma'-Ni3 (Al, Ti) strengthening phase and grain boundary regulation and control, and the diaphragm is prepared through the method of vacuum induction melting, steel mold casting, vacuum consumable smelting, forging, hot rolling, cold rolling, solution treatment, small-deformation cold rolling, cutting machining sizing, final heat treatment and diaphragm surface machining. The yield strength (Rp0.2) of the diaphragm at room temperature and 250 DEG C can reach 600 MPa or above, meanwhile, the diaphragm has good plasticity, hydrogen embrittlement resistance and fatigue resistance, and can be used as a hydrogen-contacting diaphragm in a high-pressure, especially 90 MPa hydrogen diaphragm compressor.

Description

technical field [0001] The invention relates to the field of key material components of hydrogen energy equipment, in particular to a high-strength hydrogen embrittlement-resistant diaphragm with a brand name of MP-7 and a preparation method thereof. Background technique [0002] With the development of domestic hydrogen energy, the construction of 45MPa and 70MPa hydrogen refueling stations is increasing. As the key equipment in hydrogen refueling stations, the stability, reliability and use of high-pressure hydrogen diaphragm compressors (hereinafter referred to as hydrogen compressors) Efficiency is critical to the entire hydrogen refueling station. Diaphragm is the key part of hydrogen compressor, not only to isolate lubricating oil and compress hydrogen, but also to reciprocate under the pressure transmitted by hydraulic oil, so as to achieve the purpose of boosting. It should be pointed out that during the service process, the diaphragm is faced with complex and harsh...

AI Technical Summary

Problems solved by technology

It should be pointed out that during the service process, the diaphragm is faced with complex and harsh working conditions of high pressure, hydrogen, and alternating loads and temperature cycles, which is prone to hydrogen-induced cracking, leading to diaphragm failure and damage, which hinders the development of high-pressure hydrogen compressors. and bottlenecks in engineering applications

At present, 316L is mainly used as the diaphragm material on the hydrogen side of the hydrogen compressor, and engineering practice has found that with the increase of the hydrogen pressure in service (the design pressure of the hydrogen compressor at the 30MPa hydrogen refueling station is 35MPa, and the design pressure of the 45MPa hydrogen refueling station is 52MPa and 70MPa The hydrogen refueling station is 90MPa), and the service life of the 316L diaphragm on the hydrogen side is significantly reduced (the life is even less than 1 / 10-1 / 20 of the 35MPa hydrogen refueling machine). Under variable temperature service conditions, more hydrogen will seep into the interior of the 316L diaphragm, causing the diaphragm to be prone to hydrogen-induced fracture failure; The temperature cycle, and the lower high temperature strength of 316L also limits its service life

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