-Hearth roller structure diagram show Fig 1

2. Finite element analysis of a hearth roll

1) Establish finite element model of the size of the actual structure of the hearth roller. Using software ANSYS of finite element analysis to analysis. In the modeling process of hearth roller finite element and even more simplify some the original structure appropriately：

(1). Ignored the effects of various friction.

(2). Almost all position welding are ideal for welding.

At first according to the requirements of the calculation accuracy the finite element model subdivided into a grid chart. As a result the part of thin-walled made of the shell elements. Similarly part of collar plate are made of solid elements. Completion of the corresponding element real constants and materials parameters define the operating (Young’s modulus EX = 206, the thermal expansion coefficient of 0.45E-6, Poisson’s ratio of 0.28 and a density of 7800).

2) Determine the constraints condition.

First ao all in the analysis process, except angular displacement of the x-direction on surface of the hearth roller ends is free. While other linear displacement and angular displacement are restrictions. Likewise symmetry constraints are imposed on symmetry boundary of finite element model. Above all can ensure that the symmetry of deformation.

3) Solving and result processing.

By analyzing the deformation and stress distribution of the hearth roll y-axis direction in the billet pressure, weight, torque, and the furnace temperature (1050 ℃) and other loads.

From the results shown in Figure 2

Hearth roller cone body weld stress maximum and lower weld strength here. Therefore this may explain the reason that weld fracture is the main failure mode in a way. Therefore they are possible to optimize the design through construction to improve stress distribution. Similarly to minimize the stress at the weld cone body.