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Probas de materiais

Investment casting also called lost wax casting is popular used for manufacturing precision metal casting and machining parts, every step in the process of metal casting, from pattern-making to heat treating, should be done carefully to avoid problems.

Inspección de composición química

A composición química é a única característica que identifica a especificación do material. A análise espectral é o método máis utilizado para facer a inspección da composición química dos materiais. Como sabes, a fundición de investimento tamén chamada fundición á cera perdida consiste en verter aceiro fundido no patrón de casca a través da espuela. O aceiro diferente ten as súas propias características, polo que calquera erro de composición dos elementos pode causar moitos problemas aos clientes. Antes de verter, debemos probar a composición química dos materiais en consecuencia para cada forno de aceiro fundido, coa axuda do espectrómetro podemos obter un resultado de proba preciso que mostra a composición de cada elemento contido. Ademais, co resultado da proba, poderiamos garantir que o resultado da proba cumpre coas composicións estándar do grao de aceiro especificado, entón este forno de aceiro fundido é aceptado para usar e facer un rexistro para cada lote.


Ningbo Investment Casting Co., Ltd has strictly quality control procedure in material. When ordering raw material from our audited suppliers, material certificate is requested and provided. We will randomly pick some samples to do the chemical composition in-house to have a second confirmation, and then make the labels for each batch. Finally, the labeled raw material will be delivered into our warehouse.  

Before production, we will pick sample of raw material to compare the composition of each element by spectrograph. Before the melted steel pouring, we must test the chemical composition accordingly for each furnace of melted steel, with the help of spectrometer we can get accurate composition of each element contained. The furnace of melted steel is accepted to use only the test result meets the standard compositions of the specified steel grade, and our tester will make record for each result of furnace.

And after casting or heat treatment process, our testing equipment will help us to confirm if the material composition is changed during the production process. Our spectrometer is linked to a computer. The reports are stored on the system so that the information is always available. Proper archiving of each batch testing result ensures the traceability of your product. What’s more, we will keep test bars or coupons in-house for 2 years at least.
All the testing results will be shown in a material report. In the report, you can see the material specification, quantity of samples, part number, purchase order number, heat number, each element, defined limits, testing value of each element, tester, ect. As per our quality control process, we submit our material report to our customer for final judgment if our investment castings are qualified or not.

Ensaio de propiedades mecánicas

Mechanical testing is one of the most important parts of any materials testing program. For Tensile Testing and Impact Strength testing will destroy the test piece in the process. Our steel foundry will cast test coupons alongside the product casting. Quality test results from the test coupon in same heat treatment furnace are assumed to be true of the cast product as well. So usually, we’ll do mechanical properties testing both for machined test coupon and the test bar which is machined from casting body if the investment casting is available and suitable enough to machine a test bar.
It is measured by a tensile tester, by pushing materials to failure so we can collect data to determine ultimate tensile strength, yield strength, elongation and reduction area rate and more. The testing confirms the properties comply per the specified mechanical requirements. To confirm the properties of the investment cast part, Ningbo Investment Casting lab will perform below mechanical properties testing to confirm proper investment casting quality. Tests conform to ASTM E8/E8M, E18, E384 and B578.

Probas de tracción- A destructive test process that provides ultimate tensile strength, yield strength, elongation and reduction area rate of the products. Tensile tests are usually carded out on test bar, strip or machined coupon with either circular or rectangular cross section. Test pieces are screwed into or gripped in jaws and stretched by moving the grips apart at a constant rate while measuring the load and the grip separation. Our tensile tester is linked to a computer as well. The testing results are stored on the computer for future trace.

Máquina de ensaios de tracción universal

Forza de impacto-Impact strength is measured by allowing a pendulum to strike a grooved machined test piece and measuring the energy absorbed in the break.

The test is at specified temperature while the temperature controlled. In Ningbo Investment Casting Co., Ltd., usually at least 3 charpy tests (V-notched) will be developed in the longitudinal direction in accordance with ASTM E23 or GB/T229-2007.The absorbed energy decreases at lower temperatures. We could handle the impact test Akv2(J) @+20°C, -20°C, - 40°C and -45°C depends on the requirement or castings’ service condition.

Proba de dureza-Is not an intrinsic property of a material. The values ascribed are due to a complex combination of deformation and elastic behavior. Hardness is the property that shows a materials ability to resist permanent deformation when it is under load. The greater the hardness of a material the greater the material will resist deformation. We will do hardness test when there is a hardness requirement on investment castings. For the acceptable investment castings, the tested casting hardness value must be within the given range, relevant hardness value will be listed on the MTR and submit to our customer for approval.

At Ningbo Investment Casting Co., Ltd, there are mainly three types of hardness testing, Brinell Hardness Testing, Rockwell Hardness Testing and Vickers Hardness Testing.


Ensaios de resistencia á corrosión

Normalmente non se requiren probas de corrosión a non ser que as pezas de fundición de investimento se utilicen para ambientes corrosivos ou aliaxes resistentes á corrosión, como a fundición de aceiro inoxidable, en cuxo caso pódense realizar probas no corpo de pezas de fundición de investimento e barras de proba (cupón). O noso laboratorio adoita empregar varias exposicións de niebla salina, das cales a máis frecuente é a pulverización salina neutra.

If you have any steel investment castings with all of the needed material testing, pls feel free to contact us.