K360 steel is a high-strength wear-resistant steel, widely used as an important material in mining machinery and engineering machinery. High strength steel generally has high carbon equivalent, high sensitivity to stress concentration, and poor welding performance. Adopting new controlled rolling and special heat treatment to improve strength while maintaining high strength and wear resistance. ZG30MnSi is widely used in coal mining machinery and mining machinery due to its high strength and wear resistance.
In order to study the weldability of K360 and ZG30MnSi steel plates, semi-automatic gas shielded weldability tests were conducted on K360 and ZG30MnSi steel plates with a thickness of 20mm.
(1) The empirical formula calculation method shows that the carbon equivalent of K360 and ZG30MnSi materials is moderate, and the steel has a significant tendency for cold cracking during welding. The weldability is poor, and preheating is required before welding. According to the small iron grinding test, the 20mm thick K360 and ZG30MnSi steel are welded under harsh constraint conditions. In order to prevent hardening and cold cracks in the welding Heat-affected zone, the preheating temperature should not be lower than 50 ℃.
(2) The welding heat input varies within the range of (0.832~1.81) kJ/mm, and the tensile properties of the weld metal and the room temperature impact performance of the welded joint of K360 and ZG30MnSi steel can meet the design requirements of the product.
(3) The temperature between welding passes is within the range of 100-200 ℃, and the tensile and impact properties of the welded joint can meet the design requirements of the product.
The welding process parameters of K360 and ZG30MnSi steel are controlled within the range of I=(260-300) A, U=(28-32) V, T (preheating temperature)=100-150 ℃, and T (interpass temperature)=100-200 ℃, which can ensure that all mechanical performance indicators reach ideal values.