GB/T 223.82-2018Steel and iron—Determination of hydrogen content—Thermal conductivity/infrared method after fusion under inert gas (English PDF)

6.1 General Requirements

Sampling and preparation of sample shall comply with stipulations in GB/T 20066.

6.2 Pre-furnace Sampling and Sample Preparation

Pre-furnace sampling shall adopt exclusive sampling devices. Before adopting a new pre-furnace sampling method or a new sampling device, its reliability and availability shall be evaluated; an evaluation report shall be issued for the record.

6.3 Sampling and Sample Preparation on Steel Ingot or Profile

In terms of forged or casted workpiece, the mode of sawing, digging and wire-electrode cutting is recommended for sampling. The mode of water soldering open flame cutting is not recommended for sampling.

6.4 Powdered Sample

Powdered sample needs to be taken from a great deal of evenly mixed powder. After sampling, store the sample in a clean plastic zip lock bag for a short time; store it in a vacuum bag, argon bag or sealed glass bottle for a long time. Since paper bag is water and gas permeable, it is not recommended here.

6.5 Crumbed Sample

Crumbed sample that is taken from profit or casted workpiece cannot be adopted as hydrogen determination sample, because of hydrogen transfer during the processing.

6.6 Other Samples

Materials in abnormal shapes shall be sampled in accordance with the materials. The operation of sampling can adopt certain modes of processing, such as cutting, sawing and wire-electrode cutting. Avoid overheat and contamination. Wire materials can be directly sampled.

7.1 Instrument Preparation

7.1.1 Initiate the instrument in accordance with requirements in the instruction for use provided by instrument manufacturer; confirm that flow meter and pressure gauge on the instrument are indicating the specified position.

7.1.2 If necessary, conduct air-leak check of the instrument while the power is connected, and the water-cooling system is initiated.

7.1.3 Configurate parameters of the instrument; pre-heat and stabilize the instrument. The following analytical conditions are recommended.

7.2 Blank Test

Conduct blank test before the procedure of analysis and determination. Conduct at least 3 blank value determinations; replace a new crucible in each determination. The deduction of blank value can be automatic or manual.

7.3 Calibration (any calibration procedure can be adopted)

7.3.1 Single-point calibration

7.3.1.1 Select hydrogen standard substance/standard sample (4.8) in 2 types of steel (iron); its hydrogen content shall be higher or close to the hydrogen content of the sample to be tested; the detection range of this method shall not be exceeded.

7.3.2 Multi-point calibration

7.3.2.1 Select hydrogen standard substance/standard sample (4.8) in at least 4 types of steel (iron); its hydrogen content shall be different and within the detection range of this method.

7.3.2.2 Conduct multi-point calibration in accordance with requirements in the instruction for use of the instrument. Analyze at least 3 standard substances/standard samples (7.3.2.1); each standard substance/standard sample shall be analyzed for 3 times; respectively take the average value; determine calibration curve slope and intercept through multiple points of of hydrogen content.

7.3.2.5 In accordance with the procedure described in the instruction for use of the instrument, store this calibration in the form of method; name this method.

7.3.3 Calibration frequency requirements

Instrument shall be calibrated for at least 1 time every year. When any of the abnormal circumstances emerge, instrument shall be re-calibrated to guarantee the reliability and validity of measurement.

7.4 Sample Analysis

7.4.1 Select a suitable analytical method (7.3.1.5 or 7.3.2.5). The adopted analytical conditions shall maintain consistency with the analytical conditions adopted for calibration. If the sample to be determined is powdered, corresponding standard substance/standard sample shall be adopted for calibration.

7.4.2 Input sample information in accordance with the procedure required in the instruction for use of the instrument.

7.4.3 Weigh-take 0.5 g ~ 1.0 g of sample (accurate to 0.001 g) (if there are any special […]