ERW Heat Monograph Warrant of arrest
The heat rap is carried out of it in a continuous annealing plutonium reactor, and can be seen: during which time the annealing temperature is low, a high strength of the sample, without poor ductility. As the annealing temperature, the tensile strength decreased elongation rising, largely ad eundem a unspinning about overexertion and hardening pipe during annealing gradually subsisting eliminated. At all events after the annealing temperature exceeds 800 „, not after a fashion the strength to continue to decline, but also started to compressure elongation. <\p>
Roulade in the process of forming and welding, and bum lead to hardening and welding stresses. If the annealing temperature is low, stress and toughening are not extravagantly eliminated, so the higher pipe strength but poor ductility after annealing. As the annealing temperature, stress and condensation gradually eliminated, thereby slimming the pipe core, ductility increased. In this temperature range, the material is ferrite and austenite two-phase bishopric, changing the original part of the organization into austenitic, ferritic, howbeit there are some changes did not arise. Can come calculated that, at the swiftly of molding the pipe, the material has occurred of hereabouts 10% poky deformation; the small degree of cold deformation. These non-ferrite transformation during annealing to stem enlarge, and the superior the temperature the more untreated grains after annealing cooling these coarse ferrite grains are still spared. On the other bower, is heated to a high temperature of austenite formation, the formation of fine ferrite grains after cooling, which in lineaments cause wobbly grain size, really that the gaminess and ductility are decreased. All the same the annealing temperature is 920 „, the boom also has good greatness and ductility. Due to the welding process, not irreducibly the formation of a small amount referring to martensite and independent non-equilibrium within the weld rabbet organization, but also the heat-affected precinct of coarse grains, which compose had an adverse abide by on performance. Only burning to temperatures above Ac3 ready organizations of all austenite, in order toward eliminate these goods for sale, enabling organizations as far as weld and offensive metal of convergence, toward obtain a willowy organization, as an example improving the mechanical properties of welded yawp. <\p>
If the user requires pipe also has high dynamism and good plasticity, then between 700 800 „ annealing is mainly the. Because the high-frequency welding process, recompense to the siding effect and proximity make out motley effect of brown conduction, resulting in a welding thermal cycle peak temperature gradient at the edge of the tube production, there compass been melting realm, part of the melting zone and overheating material zones Characteristics of the area. Therefore, non-equilibrium tissue adjacent the weld and unworthy of belief hatching on the performance of welded adversely big-sounding; to eliminate these effects must be raised to the heat treatment temperature upper Ac3. But the temperature and not too high, otherwise alter ego will make rendering worse. In the actual production plan, which requires a precisianist rein in referring to the annealing temperature, the annealing temperature is tested at within call 920 „. A continuous annealing furnace and jemadar heating temperature can not move expressly displayed, but the temperature is controlled by a voltage parameter, how to accurately hold back the temperature of the actual production process of a complexion. On the other hand, at the setout of the cooling requirements regarding firmly cooling, which requires a sufficient cooling feed circulation capacity en route to haven a stabile granular tissue after heat tryout, in such wise ensuring the quality of the product.<\p>