Body a wide range of materials suitable for a variety of working conditions.
Body has the following nine kinds of commonly used materials:
1. Gray cast iron, suitable for operating temperature between -15 ~ +200 ℃, nominal pressure PN ≤ 1.6MPa low-pressure valves.
2. Black heart malleable cast iron, suitable for operating temperature between -15 ~ +250 ℃, nominal pressure PN ≤ 2.5MPa of the low-pressure valves.
3. Ductile iron, suitable for operating temperature between -30 ~ +350 ℃, nominal pressure PN ≤ 4.0MPa of the low-pressure valves.
4. Carbon steel (WCA, WCB, WCC), applicable to operating temperature between -29 ~ +425 ℃, the high-pressure valves, which 16Mn, 30Mn working temperature between -40 ~ +450 ℃, often instead of ASTMA105.
5. Low carbon steel (LCB), applicable to operating temperature -46 ~ +345 ℃ low temperature valve between the valve.
6. Alloy Steel (WC6, WC9), applicable to operating temperature -29 ~ +595 ℃ The non-corrosive media, high temperature and pressure valves; WC5, WC12 apply to operating temperature between -29 ~ +650 ℃ The corrosive medium high temperature and pressure valve.
7. Austenitic stainless steel, suitable for working temperature -196 ~ +600 ℃ valve between the corrosive medium.
8. Monel alloy, mainly applied to hydrogen fluoride medium valve.
9. Copper alloy, mainly used in the working temperature of -273 ~ +200 ℃ with the valve between the oxygen pipe. Wear-resistant electrode
Body listed above is commonly used materials in the major categories, specific for each type of material, there are many different grades and different grades also apply to the different pressure levels. So, the choice of the valve body materials, should be based on different uses and different pressure levels to determine the conditions suitable for the needs of body material.
In addition, the valve body materials are titanium alloy (titanium valves), aluminum alloy (aluminum valves); plastics (plastic valves); ceramics (ceramic valves) and others.
Body Blank heat treatment process according to different materials are as follows:
1. Gray cast iron heat treatment.
In order to achieve different purposes, gray cast iron in the foundry after the heat treatment can be different. Valve production of pairs of gray cast iron valve body parts such as are often used in the foundry after the heat treatment process are: the elimination of thermal aging thermal stress and the elimination of free cementite of high-temperature annealing. Thermal aging is a necessary process. High-temperature annealing only in the casting due to the chemical composition and casting speed control cooling properly, resulting in the organization after casting primary cementite exists only use it to replace the thermal aging.
2. Carbon steel heat treatment.
Steel casting in the foundry after the casting has a large residual stress, and sometimes coarse steel pieces of the organization, and even overheating organization. These all affect the size of the stability of steel parts to reduce the mechanical properties of steel and is not conducive to the conduct of cutting. In order to eliminate thermal stress, refine, and improve the mechanical properties and improve the machining, etc., the production of the carbon steel valve body and other parts are often used in the foundry after the annealing, or normalizing and tempering.
3. Austenitic stainless steel acid-heat treatment.
Austenitic stainless steel acid-resistant major flaws are easy to produce intergranular corrosion, and can be taken to impose a certain degree of heat treatment of steel of preventive measures. Valve production of acid on the austenitic type stainless steel valve and other parts are often used in heat treatment process are: solid solution treatment (quenching), stability, processing and cryogenic treatment.
4. Martensite-type heat-resistant steel heat treatment.
Martensitic-type heat-resistant steel in the foundry should be promptly after the annealing, prevent the generation of cracks, and the holding time should be sufficient annealing (usually 4 to 8 hours). Martensitic-type heat-resistant steel annealing which aims to eliminate stress, to recrystallization, grain refinement, reduce stiffness, improve cutting performance and to organize and prepare for the final heat treatment.
Martensitic-type heat-resistant steel end-use of normalizing + tempering heat treatment.
5. High-quality carbon steel heat treatment.
High-quality carbon steel heat-treatment to 35 forged steel valve, for example, 35 # steel body to conduct normalizing after forging, heat treatment and its ultimate technical documents according to the provisions of the valve manufacturing execution, generally for quenching and tempering treatment. ball valve Trunnion Mounted Ball Valve Floating Ball Valve Top Entry Ball Valve ball valve V Type Ball Valve
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