Heat resistant Steel Precision Casting
Annealing is a heat treatment process in which steel castings are heated to 20-30°C above Ac3, kept for a certain period of time, and cooled.
The purpose of annealing is to eliminate columnar crystals, coarse equiaxed crystals, Widmanstatten structure and dendritic segregation in the cast structure to improve the mechanical properties of cast steel.
Normalizing is a heat treatment process in which steel castings are heated to 30-50°C above the Ac3 temperature to make them completely austenitized, and then cooled in still air.
The purpose of normalizing is to refine the structure of the steel so that it has the required mechanical properties, and it is also used as a preparatory treatment for subsequent heat treatment.
Quenching is a heat treatment process in which steel castings are heated to austenitization and kept for a certain period of time and then cooled in an appropriate manner to obtain martensite or bainite structure.
Especially after quenching, the tooling workpiece is directly quenched with water, quenched oil, and quenched with brine, which has special requirements for the use of tooling.
heat-resistant steel precision casting of process Requirements
Heating is one of the important processes for heat treatment of heat-resistant steel precision castings. There are many heating methods. In the past, charcoal and coal were used as heat sources, but now liquid and gas fuels are used for heating. Nevertheless, it is recommended to use electric heating for heat-resistant steel precision casting, which is not only easy to control but also free of environmental pollution.
Secondly,cooling is also an indispensable step in the heat treatment process of heat-resistant steel precision casting. Although the cooling method varies from process to process, the key is to control the cooling rate. Relatively speaking, the annealing cooling rate of heat-resistant steel precision castings is relatively slow, and the cooling rate of normalizing is faster, and the faster is the cooling rate of quenching heat-resistant steel precision casting.
When cooling, due to the different steel grades of heat-resistant steel precision casting, the requirements put forward are also different. But in short, heat treatment is a metal heat treatment process that heats the heat-resistant steel precision casting as a whole, and then cools it at an appropriate speed to obtain the required metallographic structure to change its overall mechanical properties.
Heat treatment stress of heat-resistant steel precision casting
In the heating and cooling process of heat-resistant steel precision castings, due to the inconsistency of the cooling rate and time between the surface and the core, a temperature difference is formed, which will cause uneven volume expansion and contraction to produce stress, that is thermal stress.
Under the action of thermal stress, because the surface temperature is lower than the core part, and the contraction is greater than the core part, the core part is stretched. When the cooling is over, the core part is compressed because the cooling volume contraction of the core part cannot proceed freely. pull. That is, under the action of thermal stress, the surface of the workpiece is compressed and the core is stretched. This phenomenon is affected by factors such as cooling rate, material composition and heat treatment process.
When the cooling rate is faster, the carbon content and alloy composition are higher, and the uneven plastic deformation under the action of thermal stress during the cooling process is larger and then the residual stress formed is larger.
On the other hand, due to the change of the structure of the steel during the heat treatment process, that is, the transformation of austenite to martensite, the increase in specific volume will be accompanied by the expansion of the volume of the workpiece, and the phases of each part of the workpiece will change successively, resulting in inconsistent volume growth and structure. stress.
The final result of the change in tissue stress is the tensile stress on the surface and the compressive stress on the core, which is exactly the opposite of the thermal stress.
The size of the structure stress is related to the cooling rate of the workpiece in the martensite transformation zone, the shape, the chemical composition of the material and other factors.
Q: What kinds of products do you offer?
A: Specializing in the production of various heat resistant steel precision casting, Heat-treatment Fixtures, Heat Treatment Baskets, Heat Treatment Trays, Radiant Tubes, Furnace Rollers, furnace grate bars,Smelting pot, Slag Pot, Aluminum Ingot Mold, etc.
Q: Can you manufacture Customization products?
A: Yes, We can produce both standard and special prosucts.
We can produce by your samples or technical drawings.
We can build the molds and fixtures.
Q: Can the products be customized as our need, such as put on our logo?
A: Surely our products can be customized as your need, Put on your logo is also available.
Q: What is the Warranty for our products ?
A: If any quality problems on our side occurred in this period , we will take on the shipping cost and replacement.
Q: What information do we need to provide to you in order to confirm our parts order?
A: provide us your drawings or detailed specifications for our technical staff could make the drawing.
Q: What is the delivery time of your products?
A: It depends on the inventory availability.If items needed are in stock, the delivery time would be within 7 work days, but if not the delivery time would be around 30 work days.
We will send working schedule of your order each week.
The detailed inspection picturesion by email.
Eternal Bliss Alloy Casting & Forging Co, Ltd.
What’s app: 0086-130 930 23772