Precision steel pipe pickling passivation technology elements: the purpose is to provide a pickling passivation process, the technology can reduce the material cost, at the same time, the process can increase the manufacture of precision steel pipe pickling passivation speed, reduce the manufacturing difficulty.
Pickling passivation with good tenacity: mold in the process of side impact door beams extrusion should bear at the same time significantly impact extrusion, the bending stress, and other complex load. Selected materials, so the requirement after heat treatment, should have high tenacity. Therefore, the mould Materials should have good hardenability and the uniform organization.
Pickling passivation has good thermal stability: when continuous production, the rise of temperature of the mold to or greater than 200 ℃, sometimes the use 160-180 ℃ tempering temperature of mold materials, can reduce the intensity, hardness, therefore, used in the mould of high temperature material, should be Good resistance to tempering stability.
Pickling passivation good abrasion resistance, mold should have high abrasion resistance, to ensure the normal service life, produce large quantities of qualified extrusion. In general, the precision of steel tube hardness and abrasion resistance under corresponding conditions is proportional to the. So the requirement model Provide materials not only should have corresponding hardenability, must have the high hardenability. But except hardness, determine the abrasion resistance of steel and heat treatment after the matrix organization thickness, composition, excess and mouth fire carbide precipitation phase number, size, type, degree of dispersion And red hardness, etc.
Good manufacturability: cold extrusion mold manufacturing cycle is long, complex beam impact tubes technology, high accuracy requirement. Generally must be made via the forging, machining, heat treatment, grinding or other finishing, etc. Therefore, only the manufacturability is good material, can meet the production On the need.
Understand the precision steel pipe melt dripping transition is? Drop transition process closely associated with precision steel tube product qualities, its research has the following significance:
1, affect precision steel smelting. Drop the particles, the smaller the specific surface area, the greater the smelting effect is better, and vice versa.
2, influence of arc length control. When smelting arc length through the short time, such as control of 10 mm, the length and the metal droplet size close, will cause the short circuit between electrode and molten pool, cause arc extinguishing and make the suspension melting, perhaps because frequent short circuit
Molten pool temperature change sharply. The two may destroy normal smelting, also influence the titanium ingot group on average. Therefore, smelting arc length control usually in more than 15 mm.
3, influence precision steel tube surface quality. Metal droplet distribution consequences, making a impact beam tubes small part of the metal splash and cling to the crucible; Arc on the role of the metal molten pool can cause spillage; Combined with the rotation of the molten pool and metal volatiles and impurities in the crucible Stick on wall, group successful the riser of ingot casting.
Because of riser can't very well by melting pool, and adsorption or stick the more impurities, the beginning and end of the titanium ingot can be processed flat and skinned.