Installation Standards for T-type Strainers: Differences in Welding Processes between C83600 Bronze And S31803 Duplex Stainless Steel

In the industrial field, T-TYPE STRAINERS are widely used in various fluid transmission systems due to their efficient filtering performance and reliable structural stability. And the selection of installation standards and welding processes is crucial for ensuring the long-term stable operation of the equipment. This article will focus on discussing the differences in welding processes between C83600 BRONZE and S31803 duplex stainless steel in T-TYPE STRAINER welding, and provide reference bases for relevant technical personnel in combination with actual application requirements.

I. OVERVIEW OF MATERIAL CHARACTERISTICS

(1) C83600 Bronze
C83600 BRONZE is an alloy material based on copper with a small amount of elements such as tin and zinc added. It has good mechanical properties and wear resistance, and performs particularly well in corrosive environments such as seawater. Its main components include copper, tin, zinc, etc. It has relatively high strength and hardness while maintaining a certain degree of toughness. The weldability of C83600 bronze is relatively good, but attention needs to be paid to the possible problem of hot cracks during the welding process.

(2) S31803 Duplex Stainless Steel
S31803 duplex stainless steel is a second-generation ultra-low carbon duplex stainless steel containing nitrogen. Its chemical composition includes 22% chromium, 5% nickel, 3% molybdenum, and 0.16% nitrogen. This material combines the excellent toughness of austenitic stainless steel and the high strength of ferritic stainless steel, and also performs outstandingly in terms of resistance to stress corrosion, pitting corrosion, and intergranular corrosion. The weldability of S31803 duplex stainless steel is good, but the welding process parameters need to be strictly controlled to ensure that the performance of the welded joint is consistent with that of the base metal.

II. DIFFERENCES IN WELDING PROCESSE

(1) Welding Methods
• C83600 Bronze: Manual arc welding (SMAW) or gas shielded welding (such as TIG welding) is usually adopted. When using manual arc welding, appropriate welding electrodes, such as bronze welding electrodes, should be selected to ensure that the chemical composition of the weld seam is consistent with that of the base metal. Gas shielded welding can better control the welding environment and reduce oxidation and contamination.
• S31803 Duplex Stainless Steel: Manual tungsten inert gas arc welding (TIG welding) or metal inert gas welding (MIG welding) is recommended. TIG welding can provide high-quality weld seams and avoid the mixing of impurities in the weld seams. During the welding process, the welding heat input needs to be strictly controlled to ensure the tissue balance of the welded joint.

(2) Welding Parameters
• C83600 Bronze: The welding current is generally controlled within 100 - 150 A, and the welding voltage is about 18 - 22 V. The welding speed should be moderate. Avoid too fast a speed that may lead to incomplete fusion of the weld seam or too slow a speed that may cause the weld seam to overheat.
• S31803 Duplex Stainless Steel: The welding current is usually 120 - 180 A, and the welding voltage is 20 - 25 V. The welding heat input should be strictly controlled within 1.5 - 2.5 kJ/mm to ensure that the cooling speed of the welded joint is moderate. During the welding process, the interpass temperature should be controlled below 150 °C.

(3) Shielding Gases
• C83600 Bronze: In gas shielded welding, pure argon gas or a mixture of argon gas and a small amount of carbon dioxide is usually used as the shielding gas.
• S31803 Duplex Stainless Steel: Argon gas with a purity of 99.99% must be used as the shielding gas during welding. During the welding process, argon gas also needs to be filled inside the pipe to prevent oxidation on the inner side of the weld seam.

(4) Pre-welding Preparation
• C83600 Bronze: Before welding, the welding parts need to be cleaned to remove oil, rust, and oxide scale. For thicker workpieces, a V-shaped groove can be adopted, and the groove angle is generally 60° - 70°.
• S31803 Duplex Stainless Steel: Before welding, the welding parts need to be machined to ensure that the groove surface is smooth and free from oxide scale and iron ion contamination. The groove form is usually V-shaped, the thickness of the root face is 1 mm, and the alignment gap is 2 - 3 mm.

(5) Post-welding Treatment
• C83600 Bronze: Generally, no special treatment is required after welding, but the appearance of the weld seam needs to be inspected to ensure that there are no defects such as cracks and pores.
• S31803 Duplex Stainless Steel: After welding, visual inspection and non-destructive testing (such as X-ray inspection, penetrant inspection, etc.) need to be carried out to ensure the quality of the weld seam. In some cases, post-welding heat treatment is also required to restore the performance of the welded joint.

III. INFLUENCE OF WELDING PROCESSES ON THE PERFORMANCE OF T-TYPE STRAINERS

(1) C83600 Bronze
The welding process of C83600 BRONZE directly affects its corrosion resistance and mechanical strength. Reasonable welding parameters and protection measures can effectively reduce the defects in the weld seam, thereby improving the overall performance of the filter. In corrosive environments such as seawater, a good welding process can ensure the corrosion resistance of C83600 bronze and extend the service life of the equipment.

(2) S31803 Duplex Stainless Steel
The welding process of S31803 duplex stainless steel is crucial for the structure and performance of its welded joint. By strictly controlling the welding heat input and the use of shielding gas, the proportion of ferrite and austenite structures in the welded joint can be ensured to be balanced. This structural balance can effectively improve the ability of the welded joint to resist stress corrosion, pitting corrosion, and intergranular corrosion. Meanwhile, a reasonable welding process can also ensure that the mechanical properties of the welded joint are consistent with those of the base metal.

IV. SUMMARY AND RECOMMENDATIONS

The differences in the welding processes of C83600 bronze and S31803 duplex stainless steel in T-TYPE STRAINER welding are mainly reflected in aspects such as welding methods, welding parameters, shielding gases, pre-welding preparation, and post-welding treatment. The welding process of C83600 bronze is relatively simple, but attention needs to be paid to hot cracks and oxidation problems. The welding process of S31803 duplex stainless steel is more complicated and requires strict control of welding heat input and the use of shielding gas.

In practical applications, technical personnel should choose appropriate welding processes according to specific working conditions and material characteristics. For C83600 BRONZE, it is recommended to adopt gas shielded welding and strictly control the welding parameters. For S31803 duplex stainless steel, TIG welding or MIG welding is recommended, and it is necessary to ensure that the protection measures during the welding process are in place. Meanwhile, the pre-welding preparation work and the post-welding inspection and treatment cannot be ignored to ensure the quality and performance of the welded joint.

By reasonably choosing the welding process, the installation quality and operation reliability of T-TYPE STRAINERS can be effectively improved, thereby extending the service life of the equipment and reducing maintenance costs. It is hoped that the analysis in this article can provide useful references for relevant technical personnel and contribute to the efficient operation of industrial fluid transmission systems.