Box-type tempering furnace quality appraisal

box-type tempering furnace is a standard periodic operation box-type furnace with a hot air internal circulation fan installed on the top of the furnace. It is mainly used for tempering heat treatment of alloy steel products and various metal parts, as well as light alloy heat treatment such as solid melting, annealing and aging of aluminum alloy and copper materials.
box-type tempering furnace is widely used in automobile, aviation, aerospace, machinery, metallurgy, electric power and other industries. It is commonly used in processes such as heat treatment, annealing, aging treatment, quenching and tempering of metal materials.
In the quality case of box tempering furnace, quality appraisal is an indispensable link. Zhongke Testing provides quality appraisal services for box-type tempering furnaces.

GB/9452 Method for determination of effective heating zone of heat treatment furnace
GB/T 30824-2014 Test method for temperature uniformity of gas heat treatment furnace
GB/T 33957-2017 Test and calculation method for heat balance of heat treatment furnace

box-type tempering furnaces mainly include TPH-type box-type tempering furnaces, SHR-type box-type tempering furnaces, FHS-type box-type tempering furnaces, TRS-type box-type tempering furnaces, etc.
1, TPH type box-type tempering furnace: can temper various cold and hot-rolled strip steel, pipeline pipes and other materials.
2, SHR type box-type tempering furnace: adopts circulating air intake and rapid temperature rise technology, which can quickly temper various precision parts.
3, FHS box-type tempering furnace: can be used in steel, aviation, machinery and other industries.
4, TRS box-type tempering furnace: suitable for tempering various large-scale casting workpieces, steel ingots and other materials.

was entrusted by a court to analyze the quality reasons of box-type tempering furnaces. The expert team conducted an on-site inspection to investigate the fault state of the box-type tempering furnace with large temperature difference, and simulated and calculated the cause of the failure. The quality appraisal opinion of the box-type tempering furnace was:
1. Testing process: According to the detection method of GB/9452 "Method for Determination of Effective Heating Zone of Heat Treatment Furnace", the no-load test method was adopted, and the tempering furnace was heated and kept in accordance with the process requirements. In accordance with national standards, 9-point temperature measurement is used for box-type resistance furnaces. The layout of the test points is as follows: omitted here.
2. Identification conclusion: The "box-type tempering furnace" involved was poorly sealed and the local heat dissipation was too large; the furnace structure was unreasonable, resulting in excessive local heat dissipation; the quality of the electric heating element was not good enough and easy to break, resulting in unreasonable power, which was the main reason for the large temperature difference in the box-type tempering furnace and the poor quality of the workpiece.