The decarburization test for bolts

It is important to for a factory to owned a test machine which can test whether high strength bolts are decarburized

1、 Introduction to decarburization test for bolts

Bolt decarburization test is a method of evaluating and inspecting metal materials, mainly to determine whether there is decarburization phenomenon on the surface of bolts and other similar parts. Decarbonization is a phenomenon of carbon reduction or disappearance on metal surfaces, which can have a significant impact on the performance of materials. Therefore, bolt decarburization testing is crucial to ensure product quality and safety.

2、 Standard values for bolt decarburization test

The standard value of bolt decarburization test mainly refers to the decarburization depth specified in relevant standards. According to different material and structural requirements, the standard values for bolt decarburization tests also vary. For example, GB/T 6178-2006 "Ordinary grade hexagon hex bolts and nuts" stipulates that at the specified bolt test position, the decarburization depth on the bolt surface should not exceed 10% of the thread height.

3、 Scope of application of standard values for bolt decarburization test

The scope of application of the standard values for decarburization testing of bolts includes various metal material bolts, such as steel, aluminum, nickel alloys, etc. The test standard values for bolts of different materials also vary. In practical operation, it is necessary to choose appropriate bolt decarburization test methods and standard values based on the specific situation of the bolts.

4、 The operation process of bolt decarburization test

The operation process of bolt decarburization test is divided into the following three steps:

1. Select test location and bolt cleaning: Select the specified test location, clean the bolt surface, and ensure cleanliness.

2. Heating and cooling: Heat the bolt at a high temperature of 270 ° C-300 ° C for 3-4 hours, then quench it in oil and thoroughly cool it at room temperature.

3. Measure decarburization depth: Use equipment such as an optical microscope or metallographic microscope to measure the decarburization depth on the surface of the bolt at the test location.

5、 Precautions

Before conducting the experiment, it is necessary to understand the specific situation of the test material and the test standard values, and choose the appropriate test method.

2. For bolts of different materials and structures, the test standard values may vary, and appropriate test standard values need to be selected based on specific circumstances.

During the testing process, it is necessary to strictly follow the required testing procedures to ensure the accuracy and reliability of the test results.

After the experiment is completed, it is necessary to analyze and evaluate the test results, as well as clean and maintain the test equipment and bolts.

【 Conclusion 】

The decarburization test of bolts plays an important role in the quality evaluation and safety inspection of materials, and the test standard value is one of the important criteria for judging the performance of materials. When conducting decarburization tests on bolts, it is necessary to carefully understand the test standard values, test methods, and precautions, and strictly follow the required test process to ensure the accuracy and reliability of the test results.

As a 20 years history's bolts manufactory, of course, we have such inspection machine to test our products.