Effect of Tempering Time on Hardness

 

Short - time Tempering (such as 1 - 2 hours): If the tempering time is short, the martensite decomposition is incomplete, and the precipitation amount of carbides is small and the aggregation degree is low. At this time, the decrease in the hardness of the shipbuilding steel plate is small. For example, after tempering for 1 hour, the hardness may only decrease by 5 - 10 HRC units. For some situations where it is hoped to maintain high hardness while improving other properties (such as toughness), short - time tempering is an option.

 

Long - time Tempering (such as 2 - 3 hours): As the tempering time is extended to 2 - 3 hours, the martensite is fully decomposed, and a large number of carbides are precipitated and aggregated. This will lead to a continuous decrease in the hardness of the shipbuilding steel plate. For example, after tempering for 3 hours, the hardness may decrease by 15 - 20 HRC units compared with the quenched state, making the steel softer and more suitable for the shipbuilding processes that require good machinability.

 

 

 

 

 

 

 

Size:
Width: 1500mm-4020mm
Length: 3000-18000mm
Thickness: 8-300mm

Correlation with Other Properties and Application in Shipbuilding

 

Correlation between Hardness and Toughness: The decrease in hardness during the tempering process is usually accompanied by an increase in toughness. During the voyage of a ship, the shipbuilding steel plate needs to have a certain toughness to resist dynamic loads such as wave impact and collision. By reasonably controlling the temperature and time of tempering treatment to reduce hardness and improve toughness, the shipbuilding steel plate can better adapt to the requirements of shipbuilding and use. For example, for the ship's side and other parts that are easily affected by impact, the shipbuilding steel plate with reduced hardness and improved toughness after tempering treatment can effectively prevent brittle fracture.

 

Correlation between Hardness and Machinability: After the hardness is reduced, the machinability of the shipbuilding steel plate is improved. In shipbuilding, a variety of machining operations such as cutting, welding, and bending need to be carried out on the shipbuilding steel plate. The lower hardness makes these operations easier to carry out and can reduce the possibility of cracks and other defects during the machining process. For example, when welding the shipbuilding steel plate, the lower hardness can reduce the hardness of the heat - affected zone of welding and reduce the generation of welding cracks, improving the welding quality.

 

 

 

 

 

Why Choose Us?
We take pride in our ability to provide custom solutions for our customers' unique needs.
We analyze and compare the previous products and the current technical situation of our 12X2400X5000mm Lr Ah36 Carbon Steel Plate, and develop new technical specifications and processes.
Our customers trust us to deliver high-quality Cold-rolled Steel products on time and on budget.
We strictly implement the warm and thoughtful after-sales service, adhere to the development of good professional ethics.
We offer a wide range of Cold-rolled Steel products to meet diverse customer needs.
We adhere to the customer-centric and brand-oriented business philosophy, and continue to provide customers with reliable and excellent products and services.
Our factory is committed to upholding the highest standards of safety and quality.
All staff of our company and all departments work together to combine business management, professional technology, quantitative statistical methods and ideological education.
Our Cold-rolled Steel products are known for their durability and reliability.
Relying on the superior conditions and strong advantages of mass production, we are able to meet the different needs of our customers.

Hot Tags: 12x2400x5000mm lr ah36 carbon steel plate, China 12x2400x5000mm lr ah36 carbon steel plate suppliers, factory, 1080Aaluminum, F60 Stainless Steel, Inconel800, SUS304, Austenitic Stainless Steel, S890Q