Oxygen, Nitrogen, and Hydrogen in Refractory Metals

Summary

One of the most critical chemical specifications of titanium alloys is the hydrogen content. Too high of a

hydrogen content can cause hydrides to precipitate, which can lead to embrittlement and subsequent

cracking when the alloy is stressed. Hydrogen pickup typically occurs during downstream processing steps

such as heat treating, pickling, and cleaning.

The LECO ONH836 is a simultaneous oxygen, nitrogen, and hydrogen determinator that utilizes an electrode furnace, inert carrier gas, and both infrared and thermal conductivity detection to meet the analytical needs of the refractory metal industry. 

This application note was written specifically for use with the LECO ONH836 series determinator.

Procedure - Solid Samples

Instrument calibration/drift correction.

Place the calibration/drift standard in a *** Nickel Basket, and if applicable, place the sample into the appropriate autoloader position.

Press the Analyze button on the instrument screen. After a short delay, the loading head slide-block will open.

Note: samples using automation should be placed in the appropriate autoloader position before starting the

analysis sequence. Once the sequence has started, the automatic analysis will start and end automatically.

仪器的亮点和优势：

特点和优势

·炉头区域LED照明系统

·炉头快速拆装的粉尘过滤装置

·装有自动旁路阀的可快速拆装氧水捕集装置

·**的动态流量补偿（DFC）保证热导池气体流量、压力恒定

高效脉冲炉冷却系统

·强力内循环水冷装置热交换效率

·双直流风扇保证持续冷却，不受电压波动的影响

·***电极炉头设计，提高脉冲炉

全自动分析系统（可选）

·自动清扫装置

·20位或100位全自动分析系统

·高效全自动真空除尘装置直接将粉尘排至仪器外部捕集器中，消除环境污染

改进的红外检测池技术

·***红外池的恒温绝热技术消除了外界环境温度的干扰

·长寿命的红外发射光源和无漂移的电路设计保证红外检测池的长期稳定性

·氧高低双量程采用3个碳红外检测器同时检测一氧化碳和二氧化碳，保证准确定量

Procedure - Solid Samples

Prepare the instrument as outlined in the operator's instruction manual.

Determine the instrument blank.

Login a minimum of 3 Blank replicates.

Press the Analyze button on the instrument screen. After a short delay, the loading head slide-block will open. Place a 502-344 Nickel Basket into the loading head.

Note: samples using automation should be placed in the appropriate autoloader position before starting the

analysis sequence. Once the sequence has started, the automatic analysis will start and end automatically.

Instrument calibration/drift correction

f. Clean the upper and lower electrode manually, or, if applicable, remove the crucible and press the analyze button to clean with the automatic cleaner.

g. Firmly place a graphite crucible on the lower electrode tip.

h. Press the Analyze button on the instrument screen, the lower electrode will close and the analysis sequence will start and end automatically.

i. Repeat steps 3b through 3h a minimum of three times for each calibration/drift standard used.

. Calibrate/drift following the procedure outlined in the operator's instruction manual.

新型气路管道减少气路连接阀，使得漏气，断路故障更少。氧氮氢分析仪采购

Sample Preparation

Typically, titanium and zirconium samples are chemically etched to remove surface contamination when oxygen and nitrogen are determined. However, etching can introduce hydrogen into the sample.

ASTM method E 1409 "Determination of Oxygen and Nitrogen in Titanium and Titanium Alloys by the Inert

Gas Fusion Technique", as updated in 1996, permits either etching or abrading (filing) of the test specimen.

ASTM E 1447 "Determination of Hydrogen in Titanium and Titanium Alloys by the Inert Gas Fusion Thermal

Conductivity/Infrared Detection Method" permits surface preparation by abrading (if necessary to remove

contamination). Differences in sample preparation present somewhat of a dilemma regarding simultaneous

determination of O, N, and H in titanium. However, abrading samples with a file to remove surface

contamination will yield accurate O, N, and H results. The ONH836 utilizes a high-power electrode furnace to quickly and efficiently release the target gases from within the sample, which allows for a very rapid simultaneous determination of oxygen, nitrogen, and hydrogen.