Method for inspecting inclusion of steel for low temperature pressure vessel

Abstract

The invention relates to a method for inspecting inclusion of steel for a low temperature pressure vessel. The method comprises the following sequential steps of: I, sampling a casting blank, namely cutting the casting blank produced in site to obtain a transverse specimen with the thickness between 50 and 100mm, and cutting the specimen into small blocks; II, machining the specimen, namely machining the specimen into three pieces of transverse impact energy blank specimens with volumes from 10mm*10mm*60mm to 15mm*15mm*60mm, machining into three pieces of impact specimens with volumes from 7.5mm*10mm*55mm to 10mm*10mm*55mm, and carving V-shaped slots with the depth between 2 and 4mm; III, performing a normal-temperature impact test on the impact specimens; and IV, performing an electron microscope detection, namely putting the specimens under a scanning electron microscope for detection, and making the lens of the scanning electron microscope face the fracture surfaces of the specimens. By the method for inspecting the inclusion of the steel for the low temperature pressure vessel, the conventional detection period is shortened from 10 days to 1 day, and timely and accurate information is provided for controlling the inclusion of the steel by steelmaking measures.

Description

technical field [0001] The invention relates to a detection method for steel inclusions used in low-temperature pressure vessels. Specifically, the detection method is a detection method in which samples are taken from cast slab steel materials and processed into impact samples, and the section is enlarged and observed with a microscope. Background technique [0002] The applicant trial-produced a nickel-based steel plate for low-temperature pressure vessels. This steel plate has extremely high requirements on the purity of the steel. The flaw detection standard of the steel plate adopts the European standard. Lower the judgment, resulting in greater economic losses. The metallographic method is routinely used to test the inclusions in steel, but the metallographic method can only test the inclusions on a certain surface of the steel plate, and the randomness is large, often missing inspections, and it cannot comprehensively and three-dimensionally test the inclusions in the...

AI Technical Summary

Problems solved by technology

[0002] The applicant trial-produced a nickel-based steel plate for low-temperature pressure vessels. This steel plate has extremely high requirements on the purity of the steel. The flaw detection standard of the steel plate adopts the European standard. Lower the sentence, resulting in greater economic losses

The metallographic method is routinely used to inspect the inclusions in steel, but the metallographic method can only inspect the inclusions on a certain surface of the steel plate, and the randomness is large, often missing inspections, and it cannot comprehensively and three-dimensionally inspect the inclusions in the steel

In addition, the production cycle of the steel plate is long, and it cannot provide timely information for steelmaking to control inclusions