Copper heat treatment of large forgings are mainly forged directly from the ingot, so in the heat treatment must be considered when smelting, ingot casting, forging and other processes on the casting of the internal quality of the casting, as long as the impact of the factors are chemical composition is not uniform in the presence of a variety of smelting defects; coarse grain and very uneven; more gases and impurities; larger forging stress and heat treatment stress.
The purpose of heat treatment after the forging of large forgings is to prevent white spots and hydrogen embrittlement, improve the internal organization of forgings, eliminate forging stress, reduce hardness and improve cutting performance, so as to obtain good mechanical properties or to prepare the organization for future heat treatment.317L stainless steel pipe forging belongs to the casting of large forgings. Manganese can improve the strength of steel, can attenuate and eliminate the adverse effects of sulfur, and can improve the hardenability of steel, high alloy steel with high manganese content (high manganese steel) has good wear resistance and other physical properties. Silicon it can improve the hardness of steel, but plasticity and toughness decline, electrical steel containing a certain amount of silicon, can improve the soft magnetic properties. Tungsten can improve the red hardness and thermal strength of steel, and can improve the wear resistance of purple copper tube. Chromium can improve the hardenability and wear resistance of steel, and can improve the corrosion resistance and oxidation resistance of steel. Vanadium can refine the grain organization of steel, improve the strength, toughness and wear resistance of steel.
When it is melted into austenite at high temperatures, it increases the hardenability of steel; conversely, when it is present in carbide form, it reduces its hardenability. Molybdenum can significantly improve the hardenability and thermal strength of copper alloy pipe, prevent tempering brittleness, improve the remanent magnetism and petite recalcitrance, titanium can refine the grain organization of copper alloy pipe, thus improving the strength and toughness of copper alloy pipe.
