On 2018-08-08 14:48:54
Aerospace and automotive heat treatment
What is heat treatment?
Heat treatment is the use of heat or cooling to achieve desired results, such as hardening or softening of materials. Heat treatment technology includes annealing, surface hardening, precipitation strengthening, tempering, normalizing and quenching.
In the heat treatment industry, there are usually two types of business, the first is dedicated heat treatment equipment, which is an integral part of large-scale manufacturing facilities and heat treatment parts within the enterprise. The second is commercial heat treatment equipment, which provides heat treatment to various customers and markets as a subcontracting service.
The commercial heat treatment business deals with many different types, shapes and sizes of materials. Sometimes the heating process is multi-stage and will be carried out in several different types of furnaces to achieve the expected performance. But this will bring many problems. First of all, it is impractical and sometimes impossible to monitor the process temperature of all processed parts. Secondly, if some heat treatment processes can not be properly implemented, the product performance will not meet the requirements. Generally, heat treatment belongs to finishing process, which may lead to unqualified or abandoned parts, and the cost of these parts is very high. This is especially true in the aerospace and automotive industries.
So, how can process engineers ensure that the equipment used to process the parts can achieve the expected goal? Testing the "processed" parts will know whether the processing is successful, but in order to avoid unnecessary waste and rework, it is necessary to know whether the processing can be successful before processing the parts. To achieve this, we need to develop a set of equipment test plan, use the plan to analyze the heating furnace, and then apply the analysis results to the process specification. This, in turn, ensures that the equipment used to process components can operate efficiently and accurately, resulting in repeatable and consistent results that meet the application needs of the end customer. These furnace classification specifications are commonly referred to as high temperature measurement specifications.
Specification for high temperature measurement in aerospace and automotive industries
There are many high temperature measurement specifications in these two industries. For example, in the aerospace industry, there are BAC 5621 and RPS 953 written by OEM customers, as well as national standards such as BS 2m 54 and DIN 17052-
1. There are similar standards in the automotive industry.
However, this paper will focus on the two most widely used specifications in the aerospace industry (AMS 2750) and the automotive industry (cqi-9).
These two specifications include several parts, which respectively list the requirements for instruments, thermal processing equipment, thermocouples, temperature uniformity measurement (TUS) and system accuracy test (SAT).