Metal alloy for casting steel casting in welding type bogie and steel casting

The invention provides a metal alloy for casting a steel casting in a welding type bogie. The metal alloy comprises following components: 0.15wt%-0.25wt% of carbon, 0.21wt%-0.50wt% of silicon, 0.49wt%-1.00wt% of manganese, 0.02wt%-0.06wt% of aluminum, less than or equal to 0.035wt% of phosphorus, less than or equal to 0.035wt% of sulfur, less than or equal to 0.30wt% of copper and residual amount of iron. According to the metal alloy, alloy elements mainly contain the carbon, the manganese and the silicon; the content of each component meets the requirements of UIC840-2 Supply Technical Condition of Steel Casting for Rail Vehicle; the metal alloy has a good mechanical property. An experiment result shows that the metal alloy provided by the invention has good yield strength, tensile strength, elongation rate and impact power; particularly, the elongation rate of the metal alloy provided by the invention can be up to 31.0%.