The coefficient of expansion of precision steel pipe

Method of checking can wipe with soapy water in the annealing furnace gap at each joint to see if run gas; places where gas is most likely to run into the annealing furnace tube and the tube place where seals are particularly vulnerable to wear and tear this place, always check often change. Presented before the roll forming of precision steel pretreatment process scheme; study analyzed the normalizing temperature, holding time and cooling influence of the way of raw materials microstructure and mechanical properties of the tube; identified conventional precision steel normalizing process: heating temperature (890±10)℃, the air-cooled heat 6min interspersed. Normalizing process can be completely eliminated conventional precision steel widmanstatten to match the strength and tensile yield more reasonable yield ratioσS / bσ≤0.78, elongation 5δ≥30%, cold forming and greatly improved performance avoid cold-formed cracking phenomenon.

Volume expansion coefficient can be used or the length of said length is usually represented by. Density is the mass density of the material per unit volume of the substance, the unit is kg / m3 or 1b / in3. Derived from the tensile residual stress is mainly generated by the residual tensile stress in the device during the welding process. Currently, the project is widely used to eliminate residual stress annealed after welding cooling, and cooling after welding residual stress is an important process, this approach not only a waste of energy and easy to produce larger welding residual stresses. Post weld heat treatment is a new technique to eliminate residual stress. Precision steel before welding to heat treatment temperature after warm-up and during the welding process to maintain continuous heating of the weldment temperatures after soldering using its thermal insulation cotton allowed to cool slowly. Quenching the steel pipe to increase the strength and hardness, but to reduce their plasticity. Quenching agents are commonly used in the quenching water, oil, alkali and salt solutions and the like. Tempering precision steel will have hardened precision steel re-heated to a certain temperature, and then some method of cooling called tempering. Its purpose is to eliminate the internal stress generated by quenching to reduce the hardness and brittleness, in order to obtain the desired mechanical properties. Tempering points tempering, tempering and tempering categories. More with quenching and tempering, normalizing conjunction. After quenching and tempering treatment quenching method is called quenching.