When the customer makes a stainless steel pipe order, the delivery status needs to be indicated in the contract.
Common stainless steel delivery status includes hot rolling, cold rolling, controlled rolling, normalizing, tempering, annealing, quenching, tuning, etc., hot rolling state effectively reduce energy consumption, reduce costs, can optimize the processing performance of stainless steel tubes and alloys.
Cold rolling is the use of hot-rolled stainless steel coil as the production of raw materials, after pickling to remove the oxide skin to do cold continuous rolling, the finished product is rolled hard coil, because the continuous cold deformation caused by cold hardening so that the strength of the rolled hard coil, hardness rise, toughening index decline, so its stamping performance will worsen, can only be used to produce simple
Controlled rolling is the control of rolling, that is, on the basis of adjusting the chemical composition of stainless steel pipe, by controlling the heating temperature, rolling temperature, deformation system and other technological parameters, control the change law of austenitic stainless steel tissue and the microstructure of phase change products, to achieve refinement of the Organization, enhance the strength and toughness of the purpose. The positive fire is to heat the stainless steel pipe fittings to Ac3 or above 30-50 ℃, and after a period of insulation, remove from the furnace in the air or spray water, spray or blow cooling metal heat treatment process. The aim is to make grain refinement and carbide distribution homogenization. The difference between positive fire and annealing is that the fire cooling speed is faster than the annealing cooling speed, so the normalizing tissue is finer than the annealing tissue, and its mechanical properties are also significantly enhanced.
In addition, just outside the furnace cooling does not occupy the equipment, the production rate is high, so as far as possible to use the positive fire in the production instead of annealing. Annealing is a metal heat treatment process that heats the stainless steel pipe quickly to a certain temperature and maintains a certain amount of time after cooling with the appropriate speed.
One of the most important process parameters of annealing is the maximum heating temperature, and the selection of annealing heating temperature of most alloys is based on the phase diagram of this alloy system.
Quenching refers to the heating of the stainless steel tube to a critical temperature of Ac3 or Ac1 above the temperature, after a period of insulation, so that all or part of its austenite, and then more than the critical cooling speed of cold speed cold to Ms below for martensite transformation of the heat treatment process. Tempering refers to the quenching of the stainless steel pipe, under the AC1 heating, insulation after cooling down a stainless steel material heat treatment process. Tempering treatment is the heat treatment process of high temperature tempering after quenching.
High temperature tempering refers to the tempering in the 500-650 ℃ interval.
The modulation can adjust the performance and material of stainless steel pipe to a great extent, so that the strength, plasticity and toughness of the pipe have a good performance, so as to achieve a good level of comprehensive mechanical properties.