Thermal stress analysis

Hi sir,

i have analysed thermal stress by passing the laser beam on rectangular plate (through structural mechanics module).i used stainless steel temp dependent material properties to my simulation. i used elasto plastic properties yield and tangent modulus. i have attached the properties also.i satisfied with results of deformation of plate and temperature profile. but my major problem is von mises stress exceed the ultimate stress level.

how can i reduce the stress value??

is there any possible to use smooth function.

please help me genius.