Views: 73 Author: Site Editor Publish Time: 2022-11-11 Origin: Site
Molded steel is a grade of steel used to make molds such as cold stamping tools, hot forging tools and die casting tools. Molds are the main processing tools for the production of parts in industrial sectors such as mechanical engineering, radio instruments, motors and electrical appliances.
What are the advantages of mold steel?
What is the selection method for cold working mold steel?
What are the characteristics of hot working mold steel?
1. Abrasion resistance
The wear resistance of molded steel is the most basic and one of the most important. Hardness is the main factor for wear resistance. Generally, the mold has high hardness, low loss and good wear resistance. At the same time, the wear resistance of mold steel depends on the type, quantity and shape of its carbides.
The working pressure of the mold is so high. It has to withstand high impact loads. Therefore, molded steel must have great strength and toughness to cope with such harsh working conditions. Its toughness depends on the carbon content and texture.
The main series of cold working mold steels are high hardness cold working steels, mainly used for dies requiring high pressure and wear resistance, and whose hardness is higher than HRC60-62. For molds requiring impact strength and high toughness, the hardness is lower than HRC60-62, and the most common tempering steels, spring steels, hot work molds or base steels are mainly used. For large punching tools, such as automotive outer punching parts, cast iron is mainly used. Zinc-based alloys or polymer composites are used for simple or small lifetimes.
The use of high-speed steel and ultra-high-speed steel in cold working tools is increasing rapidly. Mainly there is a high ratio of "compressive strength/hardness". And the hardness can be chosen between HRC60-70.
Powder forming steel has excellent wear resistance, and the hardness is not high HRC60-62, and it is widely used.
Carbon mold steel still has a certain range of applications for stamps with a service life of 100,000 pieces or soft material punching tools.
Since hot working molded steel works under temperature conditions, the material must have thermal strength and thermal wear resistance. To ensure the service life of the mold, the mold should be cooled, and the alternately hot and cold mold will crack, ie heat fatigue cracks. The material must also have crack resistance and heat fatigue resistance.
Material selection according to main series of thermal strength:
Low alloy tempered drop steel (6G, 6F2, 6F3) → Hot working steel with medium chromium content (H11, H12, H13) → Tungsten hot working steel (H21, H22).
Non-standard hot working steel: such as hardening 6H4 for hot-dip forging tools. When using H11, H12 and H13, thermal wear resistance cannot be met, 6H1 and 6H2 can be selected.
If hot work mold steel needs to be based on hot work wear resistance, D2, D4→M2, M4→powder steel can be selected. The high temperature wear resistance of steel bonded sintered carbide and cobalt-based sintered carbide is very high, but its heat fatigue resistance (ie cold and hot fatigue crack resistance) is very poor, and it can not be used in rapid state cooling and rapid heating.
Beizhong Group is the one-stop of large-scale comprehensive of Independent brand supporting and processor, covering tool steel: developed many new steel grade, production, sales (wholesale, retail), milling processing, vacuum heat treatment, physical and chemical testing, mold base processing and mechanical processing etc.