Molybdenum and chromium molybdenum heat-resistant steel welding rods refer to a type of low alloy steel. It has certain heat resistance performance in the working temperature range of 500-600 ℃. In general, the welding performance of pearlite heat-resistant steel is similar to that of low alloy steel. Only in terms of the chemical composition of the weld seam, strict control should be exercised over pearlite heat-resistant steel. Before welding this type of steel, most of the welded parts need to be preheated to prevent the formation of welding cracks; Post weld heat treatment is carried out to eliminate the brittleness of the welded joint and residual welding stress.