Introduction to Stainless Steel in Precision Casting

Introduction to Stainless Steel in Precision Casting

When it comes to stainless steel, there may be a misconception. It is a wrong concept to think that stainless steel will not rust. The so-called stainless steel is actually a type of steel with relatively poor rust prevention ability compared to other types of steel. For example: ordinary carbon steel. Stainless refers to the corrosion resistance of steel. So, stainless steel refers to its much stronger corrosion resistance than general steel grades. Today, precision casting manufacturer Tianyao Metal will introduce several common types of stainless steel to you.

Stainless steel is divided into ordinary stainless steel and acid resistant steel according to its corrosion resistance. According to chemical composition, stainless steel can be divided into chromium stainless steel, chromium nickel stainless steel, and chromium nickel nitrogen stainless steel. According to the matrix structure, stainless steel can be divided into ferrite type, austenite type, martensite type, austenite ferrite type, and precipitation hardening type. The commonly used types in industry include austenite, martensite, and precipitation hardening.

The common material for martensitic stainless steel is Cr13. According to different carbon content, it is divided into 0, 1, 2, 3, and 4Cr13. These types of stainless steel are chromium stainless steel. As the carbon content increases, the corrosion resistance of Cr13 steel weakens. Among them, the first three have good corrosion resistance, while the last two have decreased. But due to its high carbon content, it has higher strength and hardness. ZG1Cr13 and ZGCr13 are commonly used in casting. In addition, ZGCr17Ni2, 3 also belongs to martensitic stainless steel. But it belongs to chromium nickel stainless steel. Cr13 steel has poor fluidity, large shrinkage, and is prone to concentrated shrinkage. Therefore, the pouring temperature and speed should be increased during pouring.

Austenitic stainless steel is the most widely used. Often when purchasing household stainless steel products outside, people introduce 304 or 18-8, which is actually the most common austenitic stainless steel. The commonly used austenitic stainless steels for casting include 0Cr18Ni9, 1Cr18Ni9, 1Cr18Ni9Ti, and Cr18Ni12Mo2Ti. According to American standards, they are commonly referred to as 304, 316, and 321 stainless steels. These types of stainless steels have good casting performance and good fluidity, but they have significant shrinkage and a high probability of forming concentrated shrinkage pores. It is worth pointing out that for materials with added titanium elements, some attention should be paid to the timing of titanium addition and melting protection, otherwise it is easy to cause a low qualification rate.

The common precipitation hardening stainless steel is ZG0Cr17Ni4Cu4Nb, which is the American standard 17-4. The corrosion resistance of this steel can be higher than that of American 18-8, but it not only has higher strength, but also good plasticity, corrosion resistance, and oxidation resistance. This type of steel has good casting performance, but is prone to inclusions, so the correct casting, melting, and pouring process should be formulated.

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