In the process of petrochemical production, adverse conditions such as poor production conditions, equipment failures, illegal operations and management lag may lead to serious accidents such as personal injury, equipment damage or environmental pollution, and even directly affect the production efficiency of the enterprise even in serious cases To the health of workers, but also to the state property will bring significant losses.

Deterioration and failure of petrochemical equipment cause for many reasons, the conditions are also complicated, such as corrosion and erosion, temperature changes, pressure or load changes, wear and tear, earthquakes, wind loads and so on. Among them, the main design, manufacture and installation, caused by the use of defects. Therefore, it is often the key to ensure the safe operation of pressure vessels from the perspective of metal materials failure analysis and countermeasures.

Metallurgical defects caused by the failure of metallurgical equipment used in the manufacture of petrochemical equipment may have a variety of metallurgical defects, which often become the main reason for fracture failure, such as: component bias; casting defects, slag, porosity, cracks, etc.; Folding, heavy leather, etc .; heat treatment defects, deformation, cracks, residual stress, metal structure failure. The existence of these defects have different effects on the performance of steel.

Under certain conditions, it will lead to fracture failure. For example, the deformation of cold or hot deformation process will change the metal microstructure, the appearance of texture; in the mechanical properties, corrosion resistance showed significant direction, in the timber will not pay attention to produce layered tear and hydrogen Damage and so on. The most common flaw in welding is cold cracking. It is due to binding stress, hardened tissue and generated under the action of hydrogen. Research in this area has been relatively mature, there are a number of quantitative calculation and testing methods. In the field test, the main thing is to distinguish the nature of the crack: cold crack with transgranular, but also along the crystal; and hot cracks must be along the crystal.

In addition, attention to equipment corrosion problems. For example, about 70% of the metal components of petrochemical plants are operated under atmospheric conditions, and atmospheric corrosion has caused many metal structures to be seriously damaged. According to the latest statistics, the total failure caused by corrosion in the whole country accounted for one third of the total number of failures. Prevent corrosion and slow down the path of corrosion, mainly divided into metal corrosion and corrosion process. Which method is used depends on the situation.

There are many types of equipment failure, according to the production characteristics of enterprises and equipment status, the focus of future failure analysis should consider the following aspects: a. The proportion of failure caused by raw material defects larger, so the first thing to consider is the quality of raw materials , In particular, can not ignore the problem of equipment into this area; b. Manufacturing defects caused the largest proportion of failure, often not easy to find sufficient criteria in the analysis, it should be considered from many aspects.