• <tr id='gk79ky'><strong id='gk79ky'></strong><small id='gk79ky'></small><button id='gk79ky'></button><li id='gk79ky'><noscript id='gk79ky'><big id='gk79ky'></big><dt id='gk79ky'></dt></noscript></li></tr><ol id='gk79ky'><option id='gk79ky'><table id='gk79ky'><blockquote id='gk79ky'><tbody id='gk79ky'></tbody></blockquote></table></option></ol><u id='gk79ky'></u><kbd id='gk79ky'><kbd id='gk79ky'></kbd></kbd>

    <code id='gk79ky'><strong id='gk79ky'></strong></code>

    <fieldset id='gk79ky'></fieldset>
          <span id='gk79ky'></span>

              <ins id='gk79ky'></ins>
              <acronym id='gk79ky'><em id='gk79ky'></em><td id='gk79ky'><div id='gk79ky'></div></td></acronym><address id='gk79ky'><big id='gk79ky'><big id='gk79ky'></big><legend id='gk79ky'></legend></big></address>

              <i id='gk79ky'><div id='gk79ky'><ins id='gk79ky'></ins></div></i>
              <i id='gk79ky'></i>
            1. <dl id='gk79ky'></dl>
              1. <blockquote id='gk79ky'><q id='gk79ky'><noscript id='gk79ky'></noscript><dt id='gk79ky'></dt></q></blockquote><noframes id='gk79ky'><i id='gk79ky'></i>
                全国服务热线:021-57293980 51855511
                中文 / ENGLISH   
                首页   |  关于我们  |  生产基地  |  新闻中心  |  技术中心  |  检测中心  |  销售中心  |  工作机会  |  联系我们






                Tel:+86(0)21 5729 3980

                    +86(0)21 5185 5511

                Fax:+86(0)21 5729 1585






                天津ω 上热真空亚博在线有限公司



                左孝进  Mb:13821357588


                王思斌  Mb:18822112007




                Tel:+86(0)731 5236 2532

                Fax:+86(0)731 5236 2532

                谭秋云 Mb:15873146116



                气体氮化和离子氮化之比较  2011/4/15 

                Gas Nitride or Plasma Nitride. Well known heat treat consultant David Pye, davidpye@pyemet.com is providing us with some details about what to consider when choosing between Gas or Plasma Nitriding. April 11/11

                The choice between gas nitriding and plasma nitriding is usually a very difficult choice to make. The choice will come down to depend on;

                • Capital investment,

                • Logistics

                • Necessary surface metallurgy and control that is required for the processed component.

                Capital Investment: The capital investment always seems to be considered as the driving force for the decision. Yes, the plasma systems are more costly than with the gas nitride. That is a correct assumption. But that seems to be where it stops. When making the cost comparison, between the two process techniques will generally be finished at the purchase price line. To have a true cost comparison, one really needs to consider the cost comparison of operating costs as well as the primary investment. It will then come down to considering the corporate amortization period of depreciation. After that, it really comes down to the operating costs. Once the equipment is amortized then it comes down to the direct operating costs of the equipment. It will be seen, that after the amortization period is complete, and then operating costs of the plasma technology are reduced, because of the nature of the process. This is because of process gas usage and power costs are lower. The writer has experienced the following approximate value to obtain a conventional nitrided case, as being;

                • 100ft³ of ammonia gas for 100ft² (approximate) of available surface area. (This is based on 5 to 7 process gas volume changes per hour). It further considers process temperature and time at process temperature. The reason for the process gas volume on gas nitriding being high is simply because the process vessel is being pressurized to a slight positive atmospheric pressure to act as a ‘sweep gas’ to ensure process gas circulation within the process retort and work.

                • 3 ft³ of process gas per hour (approximately)(nitrogen and hydrogen) for 100ft² work surface area. The reason for the low flow volume is because we are only using the gas necessary to generate the activity within plasma glow seam.


                The logistics consideration will be based on the;

                • Should the process be conducted ‘in house’ or sub-contracted out to a commercial heat treater, and why?

                • What is the distance of travel from the manufacturing house to the heat treatment shop?

                • Do we have the equipment to enable us to observe and control the surface metallurgy achievable. (Laboratory sample evaluation equipment)?

                • How quickly will the processed part  be processed by the commercial heat treater?

                • Do we have the appropriate floor space to accommodate the equipment?

                • Can we maintain and service the equipment?

                Process evaluation

                The question is now, how to test, evaluate, and most importantly, how do we control the process? A small metallurgical laboratory can be developed (or it is a  pre-existing laboratory) for the process evaluation that would include the following equipment;

                • Abrasive sample cut off saw

                • A pre-grind system for rough grind with silicon carbide papers

                • A rough polish using silicon carbide papers

                • Final polish using the appropriate grade of polishing cloth and either an aluminum slurry or diamond paste

                • Micro-hardness test unit

                • Inverted metallurgical microscope

                • Sample storage dessicator

                • Fume hood for simple acid etching

                • Spill kit

                The above will enable you to process most metallurgical samples and not just nitride evaluation. The process control will come from the furnace control panel and its method of;

                • Data acquisition

                • Data storage

                • Gas delivery through either micrometer gas flow valves or mass flow controllers

                • Process gas  flow ratios

                • Temperature control

                • Time cycle control

                • Heating power control

                The above is just some of control parameters that should be observed. Nitriding (gaseous or plasma) process parameters  need to be controlled if we are to produce continuous surface metallurgy and reproducible results.

                亚博足彩    上热(上海)金属亚博在线有限公司     亚博足彩天津分公司   湘潭上热金属亚博在线有限公司
                Copyright 2011-2016 SUNRAY GROUP, LIMITED沪ICP备11022038号


                沪公网安〇备 31011602001361号