1. Material
a. If you have manufacturing experience and pay attention to the grade of material, the steel mill has, the steel management, and check whether the steel inspection report meets the requirements. This requirement is divided into two types, one is the national standard (the most common), and the other is the manufacturer’s internal control standard. It is for the stability of the heat treatment of the product, narrow the chemical composition range of the steel, and facilitate the control.
b. If you are Xiaobai, pay attention to the material, whether it is round steel or billet, and ask which steel plant is. The judgment standard refers to the article "The Secret of the Price Gap between Support Wheels"
2. Welding process
a. If you have manufacturing experience, you need to look at the process and check whether the parameters of the equipment are consistent with the process. If they do not match, the quality control ability is poor. Check if there are any control requirements for the parameters, how to ensure it, and if it is actually achieved, check it. Cut the block.
b. If you are Xiaobai, you can basically skip it, find a cut-off block, and study it as a sample to see if there are obvious appearance defects in the weld, and you can ask whether the weld is inspected for flaws.
3. Heat treatment process
a. If you have manufacturing experience, look at whether it is overall heating surface quenching or intermediate frequency quenching. Observe the consistency of the process parameter settings and the process, as well as the frequency of self-check items, whether they are implemented, whether there is quenching liquid, heating temperature, and flow rate. Records, whether there are inspection records, look at the cut pieces, etc.,
b. If you are a rookie, see if it’s the mode below
Intermediate frequency mode: (surface heating)
Overall heating surface quenching mode: (Thorough heating
Regardless of the quenching and tempering treatment, the overall heating surface quenching performance is better than that of the intermediate frequency process.
4. Machining and assembly procedures
a. Have manufacturing experience: Watch the on-site quality control process, whether there is a quality control blind zone, as well as the execution status, abnormal handling process and execution, and some inspection methods, whether there are sufficient testing methods and instruments to support
b. If you are Xiaobai: Look at the most basic product processing inner hole roughness, whether the light is not bright, whether the on-site assembly is orderly, clean, and cleanliness also have a great impact on product quality, whether there is inspection and assembly Operating standards, pay attention to the management level and the scale of the manufacturer.
The above are just the most basic concepts. These are only for some agents or manufacturers who have high demand.
