Cause Analysis of Delayed Fracture of HB450 Wear-resistant Steel

    
    Steel plate plays an important role in construction, petrochemical engineering, railway and other industries. Depending on its properties, it can be used for structures that are subject to a wide range of loads, temperatures and corrosive environments. Among them, HB450 wear-resistant steel plate is particularly important for wear-resistant construction, and its failure is also a dangerous phenomenon. This article analyzes the cause of a delayed fracture in an HB450 wear-resistant steel plate.
    
    I. Overview of HB450 Wear-resistant Steel
    
    HB450 wear-resistant steel is based on NM400 steel, supplemented by more wear-resistant elements such as chromium, molybdenum, niobium and copper, and its hardness is higher than the original NM400 steel. The wear resistance is significantly improved, and it has a higher service life. In addition, it has strong air cutting and welding performance, making it widely used in the manufacture of various wear-resistant parts.
    
    II. Causes of Delayed Fractures of HB450 Steel
    
    1. Improper installation
    
    If during the installation of the wear-resistant steel plate and the assembly process, the installation and assembling are not strictly carried out according to the requirements, such as the welding surface is steel and the gap of welding joint is not uniform, the welding welding quality is not up to standard and other reasons, the weld will be easy to form the high-stress concentration zone, the steel plate surface stress is raised greatly in severe cases, which can easily cause the delayed fracture of the worn parts.
    
    2. Load
    
    The load along the direction of the steel plate not only produces an actual stress in the steel plate, but also changes the stresses already present in the steel plate. In order to prevent the possibility of delayed fracture, the maximum tensile stress applied to the steel plate must not exceed the corresponding fatigue limit of the material.
    
    3. Temperature
    
    High temperature can cause steel plates to soften and deform, leading to reduced strength and increased fracture risk. Moreover, high temperature also increases the rate of corrosion stress, reducing the fatigue strength of steel plates and increasing delayed fracture risk.
    
    4. Chemical corrosion
    
    The corrosion of the wear-resistant steel plate will make the working environment of the part more hostile, reduce its mechanical properties, and further increase the possibility of delayed fracture.
    
    III. Prevention Measures
    
    1. Regular welding inspection
    
    Regularly check the welding stress, welding length and weld quality test to prevent the weld from forming local stress concentration zone, making it easier to identify potential problems before they worsen.
    
    2. Reasonably select strength grade
    
    When replacing a wear-resistant steel plate, it is necessary to pay attention to whether the strength grade can meet the requirements, and do not select too low strength grade, which needs to be in line with the allowable stress of the working environment for a long time.
    
    3. Properly control temperature
    
    It is necessary to avoid sudden changes in temperature or prolonged high temperature in the working environment, so as to prevent material softening and deformation, thus ensuring that the steel plate can maintain its integrity and strength.
    
    4. Anticorrosion maintenance
    
    The wear-resistant steel plate needs to maintain the electrical insulation and moisture-proof maintenance, avoid direct contact with water or corrosive liquid and vapor to prevent corrosion and reduce the risk of delayed fracture.
    
    Conclusion
    
    Delayed fracture of HB450 wear-resistant steel plate is a dangerous phenomenon, which may cause severe losses. Therefore, it is necessary to understand the possible causes and select the appropriate prevention measures in order to reduce or avoid this risk.

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