The shell of a high-pressure gas-liquid separator is made of 2205+16MnR dual-phase steel clad steel plate, and the thickness of the elliptical head is (80+4) mm. In the process of head press forming, it is necessary to ensure the mechanical properties of the head base layer and the corrosion resistance of the 2205 cladding, is difficult.

　　Due to the particularity of duplex steel materials, the mechanical properties of the head material, the corrosion resistance of the composite layer, and the geometric deviation of the head are difficult to meet the requirements of standards and working conditions at the same time. After repeated trial production, the technical difficulties in the forming of thick-walled heads with duplex steel clad plates have been effectively solved, and experience has been provided for the press forming of thick-walled heads with duplex steel clad plates in the future.

　　Performance requirements of raw materials

　　1.1 Basic material requirements

　　The base material of the clad steel plate is 16MnR. The chemical composition and mechanical properties of the steel plate in use shall not only meet the requirements of GB 6654, but also the following requirements:

　　(1) The steel plate shall be subjected to ultrasonic flaw detection, which meets the requirements of Class I of JB/T 4730;

　　(2) The inspection of non-metallic inclusions in steel plates shall be in accordance with GB 10561-2005 "Method for Microscopic Evaluation of Non-metallic Inclusions in Steel", and the results shall meet the requirements of brittle inclusions (oxides and brittle silicates), plasticity Inclusions (sulfide and plastic silicate) are not more than level 2, and the sum of the two is not more than level 4;

　　(3) The low power inspection of the steel plate should be in accordance with the provisions of GB 226-91 "Steel Macrostructure and Defects and Acid Erosion Inspection Method", and the results should meet the general porosity<2, center porosity<2, and segregation<1.5 . White spots, cracks, pores and other defects in the steel plate are not allowed;

　　(4) The grain size inspection of the steel plate should be in accordance with the provisions of GB/T 6394-2002 "Metal Average Grain Size Measurement Method", and the result should be grade 5 or above;

　　(5) The content of Sulfur in the steel plate≤0.02%.

　　1.2 Multilayer material requirements

　　The composite layer material is 2205, and its performance should not only meet the requirements of ASTM SA-240, UNS S32205, but also meet the following requirements for chemical composition, normal temperature mechanical properties and metallographic requirements. Metallographic requirements: The metallographic structure of the composite material is austenite and ferrite, of which the ferrite phase accounts for 40%-60%.

　　1.3 The requirments of Cladding steel plate

　　In addition to meeting the requirements of JB 4733, clad steel plates should also meet the following requirements:

　　(1) Composite steel plates shall be sampled one by one for performance test;

　　(2) The yield limit, strength limit, and elongation of the base steel plate in the composite steel plate should meet the requirements of JB 4733, and the impact energy value should meet the requirements of GB 6654 (the material is required to be subjected to the Charpy impact test at -20°C to meet- 20℃ Akv≥24J (one of the minimum values≥17J);

　　(3) The shear strength of the joint surface of the composite steel plate composite layer and the base layer should be ≥210MPa;

　　(4) The interface joint of the clad steel plate shall be ultrasonically tested according to JB 4733 Appendix A "Ultrasonic Testing for Explosive Stainless Steel Cladding Plate", and the results shall meet the requirements of Class B1;

　　(5) The clad steel plate should be delivered in a normalized state to ensure various mechanical properties and the corrosion resistance of the composite layer;

　　(6) After the heat treatment of the composite steel plate, it shall be qualified according to the level I specified in JB/T 4730, and the base layer and the cladding layer shall be subjected to 100% ultrasonic inspection;

　　The multi-layer is qualified for 100% PT;

　　All composite steel plates that have passed the inspection shall be polished or pickled and passivated.