搅拌车滚道在循环交变载荷的作用下，应力较大区域可能形成初始微裂纹，然后发展成为宏观裂纹，接着宏观裂纹会继续扩展，导致焊道或母材开裂。下面来分析自动上料搅拌车滚道焊缝开裂的原因。

Under the action of cyclic alternating load, the initial microcrack may be formed in the area with high stress in the mixer car raceway, and then it will develop into a macro crack, and then the macro crack will continue to expand, leading to cracking of the weld bead or base metal. Next, we will analyze the reasons for the weld cracking of the roller way of the automatic feeding mixer.

1，滚道焊缝处的应力集中

1. Stress concentration at raceway weld

原因：滚道与筒体焊接时，焊缝处经常出现应力集中。此外，搅拌筒在使用过程中，滚道与托轮处的集中载荷以及滚道截面的整体变形也都会使焊接处出现应力集中现象。

Cause: When the raceway is welded to the cylinder, stress concentration often occurs at the weld. In addition, during the use of the mixing drum, the concentrated load at the raceway and the supporting wheel and the overall deformation of the raceway section will also cause stress concentration at the welding point.

2，滚道焊缝处的残余应力

2. Residual stress at raceway weld

滚道与筒体刚度相差悬殊，一般情况下，搅拌筒筒体厚度为6mm的钢板，滚道的径向厚度在60mm左右，筒体和滚道厚度相差很大，在焊接过程中，滚道的热膨胀受到限制，并且在冷却过程中的收缩也受到限制，而筒体受限程度远小于滚道，影响到焊接应力的大小及分布不均，导致残余应力的产生。

The rigidity of the raceway differs greatly from that of the cylinder. Generally, the radial thickness of the raceway of the steel plate with the thickness of 6mm of the mixing cylinder is about 60mm, and the thickness of the cylinder and raceway differs greatly. During welding, the thermal expansion of the raceway is limited, and the contraction during cooling is also limited. The cylinder is much less restricted than the raceway, which affects the size and uneven distribution of the welding stress, resulting in the generation of residual stress.

3，滚道与筒体的刚度变化

3. Stiffness change of raceway and barrel

滚道及筒体的刚度随着车辆的使用呈递减趋势，大方量搅拌车尤为明显，刚度的减弱会加速焊道的疲劳失效，导致焊道或母材开裂。

The stiffness of the raceway and cylinder decreases with the use of the vehicle, especially for large volume agitators. The weakening of the stiffness will accelerate the fatigue failure of the weld bead, resulting in cracking of the weld bead or base metal.

当搅拌筒与滚道出现焊缝开裂时，根据焊缝开裂程度的不同，可选择相应的修复方案。具体的详细内容就来我们网站http://www.jfhntjbc.com咨询吧！

When the weld between the mixing drum and the raceway cracks, the corresponding repair scheme can be selected according to the different degree of weld cracking. Specific details will come to our website http://www.jfhntjbc.com Consult!